Question

Find the equation of tangent of y=x2 at x=1

• A. (A) y=2x−1
• B. (B) y=2x+1
• C. (C) y=x−1
• D. (D) y=x+1

Answer 1

Answer: (A)

(A) y=2x−1

Answer 2

Explanation:
Given: y=x2 and x=1As we know that equation of tangent is y−f(a)x−a=f′(a) for the function y=f(x) at x =aFirst find f(a) and f′(a)f(1)=1⇒f′(x)=2x and f′(1)=2As we know that equation of tangent is y−f(a)x−a=f′(a) for the function y=f(x) at x =ay−1x−1=2⇒y=2x−1So, the equation of tangent is y=2x−1.Hence, the correct option is (A).