JEE 2023 — Mathematics PYQ

1. A.

   5

   (Correct Answer)
2. B.

   4

3. C.

   3

4. D.

   2

Explanation

$$\text{Curve: }y=x^5-20x^3+50x+2$$

$$\frac{dy}{dx}=5(x^4-12x^2+10)$$

$$\frac{dy}{dx}=0⟹x^4-12x^2+10=0$$

$$⟹x^2\approx 11.1,0.9$$

$$⟹x\approx \pm 3.3,\pm 0.95$$

$$f(0)=2,f(1)=\text{+ve},f(2)=\text{-ve}$$

$$f(-1)=\text{-ve},f(-2)=\text{+ve}$$

Number of point the curve cut the axis = 5