Question

a+b=90
b+c=a
prove that
tana=tanb+2tanc

Answer 1

Step-by-step explanation:

a=90-b

tana=tan(90-b)

tana=cotb

tana.tanb=1

b+c=a

tan(b+c)=tana

(tanb+tanc)/(1-tanb.tanc)=tana

tanb+tanc=tana-tana.tanb.tanc

tanb+tanc=tana-tanc. (tana.tanb=1)

tanb+2tanc=tana. (proved)