If cos theta =2/3,find theta where 180°<theta<360° What is the theta?
4 Answers
Explanation:
Here,
But,
From
Hence,
Explanation:
"since "costheta>0" then "theta" is in the first or"
"fourth quadrant"
"given "180^@ < theta<360^@" we require "theta" in the"
"fourth quadrant"
theta=cos^-1(2/3)=48.2^@larrcolor(red)"in first quadrant"
rArrtheta=(360-48.2)=311.8^@larrcolor(red)"in fourth quadrant"
Explanation:
Calculator and unit circle give 2 solutions for t:
In the interval (180, 360), the answer is:
or