1
AP EAPCET 2021 - 20th August Evening Shift
MCQ (Single Correct Answer)
+1
-0

If $$f(x)=\left|\begin{array}{ccc}x & x^2 & x^3 \\ 1 & 2 x & 3 x^2 \\ 0 & 2 & 6 x\end{array}\right|$$, then the ratio $$f^{\prime \prime}(x): f^{\prime}(x)$$ is equal to

A
$$2: x$$
B
$$x^2: x$$
C
$$3 x: 2$$
D
$$6: x$$
2
AP EAPCET 2021 - 20th August Evening Shift
MCQ (Single Correct Answer)
+1
-0

If $$y=\log _{\cot x} \tan x-\log _{\tan x} \cot x +\tan ^{-1}\left(\frac{4 x}{4-x^2}\right)$$, then $$\frac{d y}{d x}$$ is equal to

A
$$\frac{1}{4+x^2}$$
B
$$\frac{4}{4+x^2}$$
C
$$\frac{1}{4-x^2}$$
D
$$\frac{4}{4-x^2}$$
3
AP EAPCET 2021 - 20th August Evening Shift
MCQ (Single Correct Answer)
+1
-0

If $$y=\sin (\sin x)$$ and $$y^{\prime \prime}+f(x) \cdot y^{\prime}+g(x) \cdot y=0$$, then $$f(x) \cdot g(x)$$ is equal to

A
$$\frac{1}{2} \sin (2 x)$$
B
$$\frac{1}{2} \cos (2 x)$$
C
$$\sin (2 x)$$
D
$$\cos (2 x)$$
4
AP EAPCET 2021 - 20th August Evening Shift
MCQ (Single Correct Answer)
+1
-0

A spherical iron ball 10 cm in radius is coated with a layer of ice of uniform thickness, which melts at a rate of 50 cm$$^3$$ /min. When the thickness of the ice is 15 cm, the rate at which the thickness of ice decreases is ........ cm/min.

A
5/6$$\pi$$
B
1/54$$\pi$$
C
1/18$$\pi$$
D
1/36$$\pi$$