Courses

# Applications of Derivatives Test- 5 Class 12 Notes | EduRev

## Class 12 : Applications of Derivatives Test- 5 Class 12 Notes | EduRev

``` Page 1

CBSE TEST PAPER-05
CLASS - XII MATHEMATICS (Calculus: Application of Derivatives)
Topic: - application of derivatives
1. The two equal side of on isosceles ? with fixed base b are decreasing at the rate of
3cm/s. How fast is the area decreasing when the two equal sides are equal to the base?

2. A men of height 2m walks at a uniform speed of 5km/h away from a lamp, past which
is 6m high. Find the rate at which the lengths of his shadow increase.

3. A water tank has the shape of an inverted right circular cone with its axis vertical and
vertex lower most. Its semi vertical angle is tan
-1
(0.5) water is poured into it at a
constant rate of 5cm
3
/hr. Find the rate at which the level of the water is rising at the
instant when the depth of water in the tank is 4m.

4.
Find the interval in which the function given by
4 3 2
3 4 36
( ) 3 11
10 5 5
f x x x x x = - - + +  is
(a) Strictly increasing (b) Strictly decreasing

5.
Show that
1
( ) tan (sin cos ) f x x x
- = + is always an increasing function in 0,
4
p
? ?
? ?
? ?

6. For the curve y = 4x
3
– 2x
5
, find all the point at which the tangent passes through the
origin.

7. Prove that the curves x = y
2
, and xy = K cut at right angles if 8k
2
= 1 
8.
Find the maximum area of an isosceles ? inscribed in the ellipse
2 2
2 2
1
x y
a b
+ = with its
vertex at one end of the major axis.

9. A tank with rectangular base and rectangular sides, open at the top is to be constructed
so that its depth is 2m and volume is 8m
3
. If building of tank costs Rs 70 per sq.
metres for the base and Rs 45 per sq. metres for sides what is the cost of least
expansive tank?

10. The sum of the perimeter of a circle and square is k, where K is some constant. Prove
that the sum of their area is least when the side of square is double the radius of circle.

11. A window is the form of a rectangle surmounted by a semi circular opening the total
perimeter of the window is 10m. Find the dimensions of the window to admit
maximum light through the whole opening.

12. A point on the hypotenuse of a triangle is at distance a and b from the sides of the
triangle. Show that the minimum length of the hypotenuse is
( )
3 2
2 3 2 3
a b + .

```
Offer running on EduRev: Apply code STAYHOME200 to get INR 200 off on our premium plan EduRev Infinity!

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

,

;