Subject

Mathematics

Class

CBSE Class 12

Pre Boards

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Sample Papers

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 Multiple Choice QuestionsLong Answer Type

31.

Evaluate: sin x + cos x16 + 9 sin 2x dx


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32.

A factory manufactures two types of screws A and B, each type requiring the use of two machines, an automatic and a hand - operated. It takes 4 minutes on the automatic and 6 minutes on the hand-operated machines to manufacture a packet of screws ‘B’. Each machine is available for at most 4 hours on any day. The manufacturer can sell a packet of screws ‘A’ at a profit of 70 paise and screws ‘B’ at a profit of Rs. 1. Assuming that he can sell all the screws he manufactures, how many packets of each type should the factory owner produce in a day in order to maximize his profit? Formulate the above LPP and solve it graphically and find the maximum profit.


Let the factory manufactures x screws of type A and y screws of type B on each day.

∴ x ≥ 0, y ≥ 0

Given that

  Screw A Screw B Availability
Automatic Machine 4 6 4 x 60 = 240 minutes
Hand operate machine 6 3 4 x 60 = 240 minutes
Profit 70 paise 1 rupee  

The constraints are

4x + 6y ≤ 240

6 x + 3y ≤ 240

Total profit

z = 0.70 x + 1y

∴l.P.P is

maximise z = 0.7 x + y

subject to,

2x +3y ≤ 120

2x + y ≤ 80

x ≥0, y ≥0

∴ common feasible region is OCBAO

Correct point Z = 0.7x + y
A (40,0) Z(A) = 28
B (30,20) Z (B) = 41 maximum
C (0,40) Z(C) = 40
O(0,0) Z(O) = 0

The maximum value of 'Z' is 41 at (30,20). Thus the factory showed produce 30 packages at screw A and 20 packages of screw B to ge the maximum profit of Rs.41


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33.

Evaluate:13(x2 + 3x + ex) dx


34.

Using integration, find the area of the region in the first quadrant enclosed by the x-axis, the line y = x and the circle x2 + y2 =32


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35.

Find the distance of the point (-1,-51-10) from the point of intersection of the line r = 2i^ -j^ + 2k^ + λ (3i^ + 4j^ + 2k^) and the plane r. (i^-j^ + k^) = 5


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