recall that
tan(x+y) = (tanx + tany)/(1-tanx*tany)
so,
cot(x+y) = (1 - tanx tany)/(tanx + tany)
Now divide top and bottom by tanx*tany
sinx(cotx+tanx)
= sinx(cosx/sinx + sinx/cosx)
= cosx + sin^2x/cosx
= (cos^2x + sin^2x)/cosx
= secx
[Note: I'm still having issues with identities with regard to trig]
Verify the Trig. identities:
(a). cot(x+y)=(cotxcoty-1)/(cotx+coty)
(b). sin0(cot0+tan0)=sec0
[Note: 0=theta symbol]
1 answer