Question

Evaluate: 4(sin430° + cos460°) - 3(cos245°- sin290°)
plz help me^_^

Answer 1

Answer:

4(sin430° + cos460°) - 3(cos245°- sin290°)

Step-by-step explanation:

4(sin430° + cos460°) - 3(cos245°- sin290°)

= 4( sin (360 + 70) + cos(360 + 100) )  - 3( cos(180 + 65)  - sin(270 + 20))

= 4(sin70 + cos 100) - 3(- cos65 + cos20)

= 4( sin(90 -20)+ 4xcos (90 + 10) + 3 xcos65 - 3xcos20

= 4xcos20  - 4xsin10 + 3xcos65 - 3xcos20

= cos20 -4xsin10 + 3xcos65