NIMCET 2017 — Mathematics PYQ
NIMCET | Mathematics | 2017The equation of the tangent line to the curve y=2xsinx at the point (π/2, π) is
Choose the correct answer:
- A.
y = 2x + 2π
- B.
y=2x
(Correct Answer) - C.
y = -2x + 2π
- D.
y=−2x
y=2x
Explanation
Concept:
The equation of tangent at point (x₁, y₁) with slope m is given by
(y−y1)=m(x−x1)
Calculations:
Given curve is y=2x sin x
Taking derivative on both side, we get
dxdy=2xcosx+2sinx
Put x=2π to find the equation of tangent at the point (2π,π).
dxdy=22πcos2π+2sin2π
dxdy=2
The equation of tangent at point (x1,y1) with slope m is given by
(y−y1)=m(x−x1)
( y- π) = 2( x- 2π) y= 2x Hence, the equation of the tangent line to the curve y= 2x sin x at the point (2π,π) is 2x.
Explanation
Concept:
The equation of tangent at point (x₁, y₁) with slope m is given by
(y−y1)=m(x−x1)
Calculations:
Given curve is y=2x sin x
Taking derivative on both side, we get
dxdy=2xcosx+2sinx
Put x=2π to find the equation of tangent at the point (2π,π).
dxdy=22πcos2π+2sin2π
dxdy=2
The equation of tangent at point (x1,y1) with slope m is given by
(y−y1)=m(x−x1)
( y- π) = 2( x- 2π) y= 2x Hence, the equation of the tangent line to the curve y= 2x sin x at the point (2π,π) is 2x.

