The value of (1 + tan 20°) (1 + tan 25°)
Answers
Answered by
1
Answer:
=2
Step-by-step explanation:
It's a consequence of the following trigonometric identity
(1+tana)(1+tanb)=2+tana+tanb−tana+tanbtan(a+b).(1)
On the one hand we rewrite
tan(a+b)=tana+tanb1−tanatanb
as
tanatanb=1−tana+tanbtan(a+b).(2)
On the other hand setting x=tana and y=tanb in the algebraic identity
xy=(1+x)(1+y)−1−x−y
yields:
tanatanb=(1+tana)(1+tanb)−1−tana−tanb.(3)
If we equate (3) to (2), then we get
(1+tana)(1+tanb)−1−tana−tanb=1−tana+tanbtan(a+b),
from which (1) follows. For a=20∘,b=25∘ we obtain
(1+tan20∘)(1+tan25∘)===2+tan20∘+tan25∘−tan20∘+tan25∘tan(45∘)2+tan20∘+tan25∘−tan20∘+tan25∘12.(4)
hope it helps
Answered by
0
Answer:
- yu7ytygyytfgghjb for the use 6tyyuyrv. gg be ok with you and your family are well known as auto the day before yesterday and today is a good time for you and I will give you 3ydy y the hell is this the the the intended recipient please notify us immediately and delete the message and any files transmitted are confidential is intended recipient or an employee of stock Guru is sling bag of stock Guru is born
Similar questions