Question

Verify the identity. tan (pi - x) = -tan x

Answer 1

first of all write tan(pi-x) as [sin(pi-x)]/[cos(pi-x)]
then you use use these formulas: sin(a-b)=sinacosb-sinbcosa
cos(a-b)=cosacosb+sinasinb

Answer 2

also you must know the values for sin(pi)=0 and cos(pi)=-1

Answer 3

can you work out the problem, i'm totally lost

Answer 4

tan(pi-x)= [sin(pi-x)]/[cos(pi-x)]=>
=>tan(pi-x)=[sin(pi)cos(x)-sin(x)cos(pi)]/[cos(pi)cos(x)+sin(pi)sinx]
since sin(pi)=0 and cos(pi)=-1;"do the math"
=>tan(pi-x)=sinx/-cosx=-tanx q.e.d

Answer 5

oh okay, thank you.