If x4 + 2x3 + ax2 + bx + 9 is a perfect square, where a and b are positive real numbers, then the values of a and b are
a = 5, b = 6
a = 6, b = 7
a = 7, b = 6
a = 7, b = 6
If a2 + b2 + c2 = 16, x2 + y2 + z2 = 25 and ax + by + cz = 20, then the value of  is
C.
The value of x which satisfies the equationÂ
is
(a2 + b2 + c2)
- (a2Â + b2Â + c2)
(a2 + 2b2 + c2)
(a2 + 2b2 + c2)
Δ ABC is similar to ΔDEF. If the area of ΔABC is 9 sq. cm. and the area of ΔDEF is 16 sq. cm. and BC = 2.1 cm, then the length of EF will be
5.6 cm
2.8 cm.
3.7 cm.
3.7 cm.
A chord of a circle is equal to its radius. The angle subtended by this chord at a point on the circumference is
80°
60°
30°
90°
Let two chords AB and AC of the larger circle touch the smaller circle having same centre at X and Y. Then XY = ?
BC
1/2 BC
1/3 BC
2/3 BC
Let G be the centroid of the equilateral triangle ABC of perimeter 24 cm. Then the length of AG is
2√3 cm
8⁄√3 cm
8√3 cm
3√8 cm
A and B are the centres of two circles with radii 11 cm and 6 cm respectively. A common tangent touches these circles at P and Q respectively. If AB Â = 13 cm, then the length of PQ is
13 cm
17 cm
8.5 cm
12 cm