A. 600

B. 900

C. tan-(1/2)

D. tan-(5/7)

If the rate of change in y=2x^{3}+3x^{2}-30x+7 is 6 times the rate of change in x, then x=

If x is real, the maximum value of 3x^{2}+9x+17/3x^{2}-9x+17 is

If there is a possible error of 0.02 cm in the measurement of the diameter of a spare then the possible percentage error in its volume when the radius 10 cm is

The maximum value of x^{4}+3x^{3}-2x^{2}-9x+6 is

The points on the curve y=x^{2}+√1-x^{2} at which the tangent is perpendicular to x-axis are