(tanθ + cotθ)² = sec²θ + csc²θ
<u>Expand left side</u>: tan²θ + 2tanθcotθ + cot²θ
<u>Evaluate middle term</u>: 2tanθcotθ =
= 2
⇒ tan²θ + 2+ cot²θ
= tan²θ + 1 + 1 + cot²θ
<u>Apply trig identity:</u> tan²θ + 1 = sec²θ
⇒ sec²θ + 1 + cot²θ
<u>Apply trig identity:</u> 1 + cot²θ = csc²θ
⇒ sec²θ + csc²θ
Left side equals Right side so equation is verified
Answer:
V=πr6^2h
/3
Step-by-step explanation:
Answer:
(b) the unknown angle is 80°
Step-by-step explanation:
The unkown angle is:
[2(x-10)]°
Substituting "x" by 50 (part a)
[2(50-10)]°=[2(40)]°=80°