Question

how do you add 3 of the same trgio functions?
example:
sin 0 + sin 90 + sin 180

i did the formula
sin(a) + sin(b) = (2)(sin(a+b/2)(cos(a-b/2)

but its gud for 2 only... help me for 3

Answer 1

to make it easier to understand
\[\sin (a) + \sin(b) = 2 \times \sin(\frac{ a+b }{ 2 }) \times \cos(\frac{ a-b }{ 2 })\]

Answer 2

why to do all that circus ?
dont we knw that sin 0 = 0, sin 90 = 1, sin 180 = 0 ?

Answer 3

subbing them and adding gives,

0 + 1 + 0

= 1

Answer 4

??

Answer 5

sorry. we just started trigo. its our assignment and i hav no clue.

Answer 6

ohk,

Answer 7

did they cover unit circle yet ?

Answer 8

did they teach u about unti circle ?

Answer 9

yep i hav the table... but we hav to evaluate it. and show the proccess

Answer 10

i knw their value in the quadrantal angles and stuff. all i need is the process

Answer 11

ok i wont be useful i guess, im not getting the purpose of q oly :|

Answer 12

q?

Answer 13

question

Answer 14

oh ok then... but ur first reply... all you hav to do is to replace the value of sine. like sin 0 = 0 and then just add 3 of then so we'll get 1? is that the easy way?

Answer 15

i wud do that lol,
the other way u trying makes no sense to meh

Answer 16

oh i see. nyways thnx alot :)

Answer 17

np :)