How do you find Tan 22.5 using the half angle formula?
1 Answer
Jul 19, 2015
Find tan (22.5)
Answer:
Explanation:
Call tan (22.5) = tan t --> tan 2t = tan 45 = 1
Use trig identity:
-->
Solve this quadratic equation for tan t.
There are 2 real roots:
tan t = -b/2a +- d/2a = -2/1 + 2sqrt2/2 = - 1 +- sqrt2
Answer:
Since tan 22.5 is positive, then take the positive answer:
tan (22.5) = - 1 + sqrt2