Chapter 3.6, Problem 1PQ

a.

To determine

To determine the sign (+ or -) that yields correct formula for:

  $\frac{d}{dx}\left(\sin x+\cos x\right)=\pm \sin x\pm \cos x$

b.

To determine

To determine the sign (+ or -) that yields correct formula for:

  $\frac{d}{dx}\left(\sec x\right)=\pm \sec x\tan x$

c.

To determine

To determine the sign (+ or -) that yields correct formula for:

  $\frac{d}{dx}\left(\cot x\right)=\pm {\csc }^{2}x$