Subject

Mathematics

Class

CBSE Class 12

Pre Boards

Practice to excel and get familiar with the paper pattern and the type of questions. Check you answers with answer keys provided.

Sample Papers

Download the PDF Sample Papers Free for off line practice and view the Solutions online.
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 Multiple Choice QuestionsLong Answer Type

11.

Show that the height of the cylinder of maximum volume, which can be inscribed in a sphere of radius R is  Also find the maximum volume. 

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12.

Find the equation of the normal at a point on the curve x2 = 4y which passes through the point (1, 2). Also, find the equation of the corresponding tangent.

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 Multiple Choice QuestionsShort Answer Type

13.

Write the degree of the differential equation straight x cubed open parentheses fraction numerator straight d squared straight y over denominator dx squared end fraction close parentheses squared space plus space open parentheses dy over dx close parentheses to the power of 4 space equals space 0

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14.

If a unit vector straight a with rightwards arrow on top space equals space straight x straight i with hat on top plus 2 straight j with hat on top minus straight z straight k with hat on top and straight b with rightwards arrow on top space equals space 3 straight i with hat on top minus straight y straight j with hat on top plus straight k with hat on top are two equal vectors, then write the value of x+y+z.

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15.

If a unit vector straight a with rightwards arrow on top makes angle straight pi over 3 space with space straight i with hat on top comma space space space straight pi over 4 space with space straight j with hat on top space and space acute space angle space straight theta space with space straight k with hat on top comma space then find the value of straight theta.

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16.

Find the Cartesian equation of the line passes through the point (-2, 4, -5) and is parallel to the line fraction numerator straight x plus 3 over denominator 3 end fraction equals fraction numerator 4 minus straight y over denominator 5 end fraction equals fraction numerator straight z plus 8 over denominator 6 end fraction.

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17.

The amount of pollution content added in air in city due to x-diesel vehicles is given by straight P left parenthesis straight x right parenthesis space equals space 0.005 straight x cubed plus 0.02 straight x squared plus 30 straight x. Find the marginal increase in pollution content when 3 diesel vehicles are added and write which value is indicated in the above questions.

225 Views

18.

Show that the function f in straight A space equals space straight R to the power of minus open curly brackets 2 over 3 close curly brackets space defined space as space straight f left parenthesis straight x right parenthesis space equals space fraction numerator 4 straight x plus 3 over denominator 6 straight x minus 4 end fraction space is space one minus one space and space onto. space Hence space find space straight f to the power of negative 1 end exponent.

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19.

Differentiate the following function with respect to x:
left parenthesis log space straight x right parenthesis to the power of straight x plus straight x to the power of log straight x

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20. If space straight y space equals space log space open square brackets straight x space plus space square root of straight x squared plus space straight a squared end root close square brackets comma space show space that space left parenthesis straight x squared space plus space straight a squared right parenthesis space fraction numerator straight d squared straight y over denominator dx squared end fraction space plus straight x dy over dx space equals space 0


Given,


straight y space equals space log space open square brackets straight x space plus space square root of straight x squared space plus space straight a squared end root close square brackets space

straight y space equals space log space open square brackets straight x space plus space square root of straight x squared space plus straight a squared end root close square brackets...... space left parenthesis straight i right parenthesis

Differentiating space left parenthesis 1 right parenthesis space straight w. straight r. straight t space space straight x comma space we space get
dy over dx space equals space fraction numerator 1 plus fraction numerator straight x over denominator square root of straight x squared plus straight a squared end root end fraction over denominator straight x space plus space square root of straight x squared space plus space straight a squared end root end fraction

rightwards double arrow space dy over dx space equals space fraction numerator 1 over denominator square root of straight x squared space plus space straight a squared end root end fraction space space space space space..... space left parenthesis ii right parenthesis

rightwards double arrow space straight x dy over dx space equals space fraction numerator straight x over denominator square root of straight x squared space plus space straight a squared end root end fraction space space space space space space.... space left parenthesis iii right parenthesis

Again comma space differentiating space left parenthesis ii right parenthesis space straight w. straight r. straight t space straight x comma space we space get

fraction numerator straight d squared straight y over denominator dx squared end fraction space equals space fraction numerator negative begin display style fraction numerator 2 straight x over denominator 2 left parenthesis straight x squared space plus space straight a squared right parenthesis to the power of begin display style 1 half end style end exponent end fraction end style over denominator left parenthesis straight x squared space plus space straight a squared right parenthesis end fraction

rightwards double arrow space fraction numerator straight d squared straight y over denominator dx squared end fraction space equals space minus fraction numerator straight x over denominator left parenthesis straight x squared space plus space straight a squared right parenthesis to the power of begin display style 3 over 2 end style end exponent end fraction

rightwards double arrow space left parenthesis straight x squared space plus space straight a squared right parenthesis fraction numerator straight d squared straight y over denominator dx squared end fraction space equals space minus fraction numerator straight x over denominator square root of straight x squared space plus space straight a squared end root end fraction space space... space left parenthesis iv right parenthesis

adding space equation space left parenthesis iii right parenthesis space and space left parenthesis iv right parenthesis comma space we space get

left parenthesis straight x squared space plus space straight a squared right parenthesis space fraction numerator straight d squared straight y over denominator dx squared end fraction space plus space straight x dy over dx space equals space minus fraction numerator straight x over denominator square root of straight x squared plus straight a squared end root end fraction space space plus fraction numerator straight x over denominator square root of straight x squared space plus space straight a squared end root end fraction space equals space 0

rightwards double arrow space left parenthesis space straight x squared space plus space straight a squared right parenthesis space fraction numerator straight d squared straight y over denominator dx squared end fraction space plus space straight x dy over dx space equals space 0

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