180k views
1 vote
Cos(8x+21)=sin(-2x+51) Find the two angles represented in degrees ??? Someone help its 1am I can't do this

User TGlatzer
by
4.4k points

1 Answer

0 votes

Answer:

45 and 135degrees

Explanation:

Cos(8x+21)=sin(-2x+51) Find the two angles represented in degrees ??? Someone help its 1am I can't do this

In trigonometry, cosx = sin(90-x)

Hence:

Cos(8x+21) = sin(90-(8x+21))

Cos(8x+21) = sin(90-8x-21)

Cos(8x+21) = sin(-8x+69)

Substituting into the expression given, :

sin(-8x+69) = sin(-2x+51)

-8x+69 = -2x+51

-8x+2x = 51-69.

-6x = -18.

X = 18/6

X = 3

Since the angles 8x+21

Angle = 8(3)+21

Angle = 45

The angles represented in degrees are 45 and (180-45) = 135degrees

User Xavier Priour
by
5.2k points