find the derivative of each of the following

Question

1) f(x)=6x-11/8x+1

 

2) f(x)=(5x-2)(2x+3)/x-4

 

3) f(x))=√¯8-5x

 

 

Answer 1

For f(x) = 6x − 11/8x + 1:

Take f'(x) as 6 − [(8x)(0) − 11(8)]/(8x)² + 0

or 6 + 11/8x².

For f(x) = (5x − 2)(2x + 3)/x − 4:

Rewrite f(x) as {[10x² +11x − 6]/x} − 4.

Take f'(x) as {x(20x + 11 − 0) − [10x² +11x − 6](1)}/x² − 0

or [20x² + 11x − 0 − 10x² − 11x + 6](1)/x²] or

[10x² + 6]/x².

For f(x) = √8 − 5x:

Take f'(x) as 0 − 5

or -5.