The curve, C has equation y = 2x^2 +5x +k. The minimum value of C is -3/4. Find the value of k.

Notes: At the minimum point of the curve, the gradient is = 0. You can find the gradient of a curve by taking the derivative of a point in the curve. We also know that when the curve is at a minimum, y =-3/4.With this is mind, you can solve the question by taking these steps:Step 1 : Differentiate the equation of the curve get 4x+5 , Step 2: To find where the curve is at a minimum, set the dy/dx = 0. so 4x+5=0 therefore, we find x= -5/4.Step 3: We know At the minimum points, x= -5/4 and y=-34 so we can substitute these into the equation of the curve to find the unknown variable k. k = 19/8

BH
Answered by Baraqat H. Maths tutor

14805 Views

See similar Maths A Level tutors

Related Maths A Level answers

All answers ▸

If 2 log(x + a) = log(16a^6), where a is a positive constant, find x in terms of a


Simplify (7+sqrt(5))/(sqrt(5)-1), leaving the answer in the form a+b*sqrt(5)


find dy/dx= x^2 +x^3


Differentiate with respect to x: 4(x^3) + 2x


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:

© 2026 by IXL Learning