y = 4 x^2 -2 x
in general derivative of x^n = n x^(n-1) so
dy/dx = 4 * 2 x^1 - 2 x^0
8 x - 2
Now if you have not had that relation you have to do it from the definition
dy/dx = (y at x+h - y at x) /h as h-->0
y at x+h = 4 (x+h)^2 - 2 (x+h)
= 4 x^2 + 8 x h +4 h^2 - 2 x - 2 h
y at x = 4 x^2 - 2 x
difference over h = 8 x + 4 h - 2
as h-->0 that is
8 x - 2
as we already knew
Answer this Question
calculus - Consider the function below. f(x) = 4x2 - 5x (a) Find f '(2). (b) Use...
pre cal - Factor completely: 3x^2(4x2 + 1)^8 + 64x^4(4x2 + 1)^7.
calc - derivative of (x^3/6)+(1/2x)? i got (x^2/2)-(1/2x^2) is that correct? and...
calculus - Construct a sign chart for the derivative. Then determine the ...
Math - Find the shortcut. Solve these problems. Then find and explain a shortcut...
Calculus - derivatives - Okay, I want to find the derivative of (x^x)^(x^x)... ...
Algebra - Below is a "complete the square problem" from a math help site on the ...
Calculus - Find the derivative: h(x)=7x/sqrt(5-2x) Using the chain rule...I ...
pre-calculus - find the derivative of y=(3x+1)^2 y= square root 13x^2-5x+8
Calculus - 1.) Find the derivative of tan (sec x). 2.) Find the derivative if 1/...