When a circular oil drop expands on water, its area increases at the uniform rate of 40sq. cm per minute. The rate of increase in the radius when the radius 5 cm is

The two curves x²+y²=25, 2x²-9y+18=0

The minimum value of x³-9x²+24x-12 is

The maximum value of x²-x+1/ x²+x+1 is

If y=x³-ax²+12x+5 is increasing for all real values of x, then a lies between

Two tangents are drawn from the point (-2, -1) to the parabola y² = 4x. If α is the angle between those tangents then tan α =

The slope of the tangent to the curve x²+y² =4 at (√2, √2) is

The equation of the normal to the curve y²=x³/2a-x at (a, a) is

The point on the curve x²=2y which is closest to the point (0, 5) is

The approximate change in y, when y=x²+2x, x=3, δx=0.01 is