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

15078 Views

See similar Maths A Level tutors

Related Maths A Level answers

All answers ▸

(19x - 2)/((5 - x)(1 + 6x)) can be expressed as A/(5-x) + B/(1+6x) where A and B are integers. Find A and B


y = 4x^3 - 5/x^2 Find dy/dx


Use the substition u = cos(x) to find the indefinite integral of -12sin(x)cos^3(x) dx


A curve C is defined by the parametric equations x=(4-e^(2-6t))/4 , y=e^(3t)/(3t), t doesnt = 0. Find the exact value of dy/dx at the point on C where t=2/3 .


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