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

Answered by Baraqat H. Maths tutor

13456 Views

See similar Maths A Level tutors

Related Maths A Level answers

All answers ▸

What is product rule differentiation?


Differentiate: y = 3x^2 + 4x + 1 -4x^-1


The curve C has equation y = 3x^4 – 8x^3 – 3 (a) Find (i) dy/dx (ii) d^2y/dx^2 (3 marks) (b) Verify that C has a stationary point when x = 2 (2marks) (c) Determine the nature of this stationary point, giving a reason for your answer. (2)


The cubic polynomial f(x) is defined by f(x) = 2x^3 -7x^2 + 2x + 3. Given that (x-3) is a factor of f(x), express f(x) in factorised form.


We're here to help

contact us iconContact usWhatsapp logoMessage us on Whatsapptelephone icon+44 (0) 203 773 6020
Facebook logoInstagram logoLinkedIn logo

© MyTutorWeb Ltd 2013–2025

Terms & Conditions|Privacy Policy
Cookie Preferences