Find the equation of the tangent to the curve y = 3x^2 + 4 at x = 2 in the form y = mx + c

There are two main steps. First find the gradient of the curve at x = 2 (m). This is done by differentiating the curve equation y = 3x^2 + 4 to get dy/dx = 6x. By plugging in x = 2, we get the gradient of the tangent, m, as 62 = 12. Then we need to find the y intercept of the tangent, c. We make c the subject, so c = y - mx. We worked out what m is (12) so we just need a set of coordinates x,y which lie on the tangent. The easiest point is where the tangent meets the curve. We know x = 2 so plugging that into the curve equation gives y = 3(2^2) + 4 = 16. Now we have values of x,y,m we can find c. c = 16 - 12*2 = -8. Therefore the final answer is y = 12x - 8

Answered by Maths tutor

5362 Views

See similar Maths A Level tutors

Related Maths A Level answers

All answers ▸

What is integration?


Find the minimum value of the function, f(x)= x^2 + 5x + 2, where x belongs to the set of Real numbers


C1 June 2014 Q)4 - https://pmt.physicsandmathstutor.com/download/Maths/A-level/C1/Papers-Edexcel/June%202014%20QP%20-%20C1%20Edexcel.pdf


Find the values of x where the curve y = 8 -4x-2x^2 crosses the x-axis.


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