Practicing Success

Target Exam

CUET

Subject

-- Mathematics - Section B1

Chapter

Application of Integrals

Question:

The slope to the curve y = f(x) at (x, f(x)) is 2x + 1. If the curve passes through the point (1, 2), then the area of the region bounded by the curve y = f(x), the x-axis and the line x = 1 is

Options:

5/6

6/5

1/6

6

Correct Answer:

5/6

Explanation:

We are given that $\frac{dy}{dx}=2x+1$

⇒ y = x2 + x + c, and since the curve passes through the point (1, 2), c = 0.

Hence the curve is y = x2 + x (see the figure); the required area $=\int\limits_0^1y\,dx=\int\limits_0^1(x^2+x)dx=\frac{5}{5}$.

Hence (A) is the correct answer.