Answer:
see explanation
Step-by-step explanation:
Using the double angle identity for sine
sin2x = 2sinxcosx
Consider left side
cos20°cos40°cos80°
= (2sin20°cos20°)cos40°cos80°
= (2sin40°cos40°)cos80°
= (sin80°cos80° )
= (2sin80°cos80° )
= . sin160°
= . sin(180 - 20)°
= . sin20°
= = right side , thus proven
I think the answer is 90 degrees
46 -2c
46 decreased by means 46 minus
Twice c would be c times 2
Answer:
-51
Step-by-step explanation:
PEMDAS suggests you start with parenthesis
10+9•(-3)2-(7)
10-(27)2-(7)
10-54-7
-51
First we divide 102 by 12.75 to get the hours which is 8 hours. So it would take 8 hours