Question #18b64

1 Answer
Mar 18, 2017

13.23

Explanation:

tanx+1tanx=2
tan2x+1=2tanx
tan2x2tanx+1=0
Solve this quadratic equation for tan x.
Since a+ b + c = 0, use shortcut. There are 2 real roots:
tan x = 1 and tanx=ca=12.
a. tan x = 1 --> x=π4
10x10π45π2π2
tan10x+cot10x=tan(π2)+cot(π2)= Inf. + 0 = Infinity (rejected)
b. tanx=12 --> x=26565
10x=26565
tan10x+cot10x=tan(265.65)+cot(265.65)=
=13.15+0.08=13.23