Find the equation of the tangent to the curve y = (2x -3)^3 at the point (1, - 1), giving your answer in the form y = mx + c.

y = (2x -3)^3

y = (2x)^3 + 3.((2x)^2)(-3) + 3.(2x).(-3)^2 + (-3)^2 using Pascal's Triangle.

y = 8x^3 - 36x^2 + 54x - 27 

dy/dx = 24x^2 - 72x + 54

at point (1,-1); dy/dx = 24 -72 + 54 = 6

Therefore tangent line is of the form y=6x + c

at point (1,-1); -1=6.1 + c

Therefore c = -7 and tangent line is y = 6x - 7.

RS
Answered by Robert S. Maths tutor

12701 Views

See similar Maths A Level tutors

Related Maths A Level answers

All answers ▸

A rollercoaster stops at a point with GPE of 10kJ and then travels down a frictionless slope reaching a speed of 10 m/s at ground level. After this, what length of horizontal track (friction coefficient = 0.5) is needed to bring the rollercoaster to rest?


Given that y = x^4 tan(2x), find dy/dx


Integrate xsin(x) with respect to x


When Integrating by parts, how do you know which part to make "u" and "dv/dx"?


We're here to help

contact us iconContact ustelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

MyTutor is part of the IXL family of brands:

© 2025 by IXL Learning