If sinA=0.8& A lies between 90°and 180° find the value of tan1/2A
use your half-angle formula:
tan(A/2) = (1-cosA)/sinA
you can easily find cosA, and then just plug and chug.
tan(A/2) = (1-cosA)/sinA
you can easily find cosA, and then just plug and chug.