A rod of 10 feet long moves with its ends A and B always on the axes of x and y respectively. If A is 8ft from the origin and is moving away at the rate of 2ft per second. At what rate the area formed by AB and the axes changing …?

The circumfence of a circle measured as 14cm with   an error of 0.01 cm. the approximate percentage error in the area of the circle is

In measuring the circumfence of a circle, there in an error of 0.05 cm. if with this error the circufence of the circle is measured of the circle is measured as c cm, then the percentage error in area is

The slant height of a cone is fixed as 7 cm. if the rate of increase I its height is 0.3 cm/sec, then the rate of increase of volume when height 4 cm is

Through the point (2, 3) a straight line is drawn making positive intercept on the coordinate axes. The area of the triangle thus formed is least, when the ratio of the intercepts on the x and y axes is

In measuring the vertical angle  of the sector of acircle of radius  30cms, an error of  1⁰ is made. The error in the area of the sector is

The radius of a sphere is 3 cm. if an error of 0.03 cm is made in measuring the radius of the sphere, then the error in surface area is

The function f(x)= x³-9x²+15x+25 is decreasing in

The radius and height of a cylinder are measured as 5cm and 10 cm respectively and there is an error of 0.02 cm in both the measurements. The approximate error in the volume is

Water flows into a conical  vessel is at the rate of 5 cubic cm per sec. if the semi vertical angle of the vessel is 30⁰, then the rate of increase of water level when the water level in the vessel is 6 cm is