Question

5.
Show that cos 55 + cos 65 + 175 = 0​

Answer 1

Answer:

your answer is given below

Step-by-step explanation:

5.(cos55+cos65)+175

(cos55+cos65)+175= 2cos(55+65/2)cos(55-65/2)+175

2cos(55+65/2)cos(55-65/2)+175= 2cos(120/2)cos(-10/2)+175

2cos60cos(-5)+175

2cos60cos(-5)+175= 2×1/2 cos5+175

2×1/2 cos5+175= cos5+cos(180-5)

cos5+cos(180-5)= cos5-cos5

= 0

Answer 2

Answer:

Hey!!

Step-by-step explanation:

pls go through the attachments for your answer...

Hope it helps...

:-)