Find the slop of the tangent to the curve y=(10-sqrt x)(5+sqrt x) at x=25

2 answers

slope**
First find the derivative as a product:
d((10-sqrt x)(5+sqrt x))/dx
=(10-sqrt(x))((1/2sqrt(x))+(5+sqrt(x))(-1/2sqrt(x))
=(10-sqrt(x)-5-sqrt(x))/2sqrt(x)
=(5-2sqrt(x))/2sqrt(x)
Evaluate dy/dx at x=25