Answer:
- 0.944
Step-by-step explanation:
We know that,
cos 3A = 4 cos³A - 3 cos A (formula)
So,
If cos A = 0.4,
cos 3A = 4 cos³A - 3 cos A
cos 3A = 4 × (0.4)³ - 3 × (0.4)
cos 3A = 4 × 0.064 - 1.2
cos 3A = - 0.944
Hope it helps ⚜
Answer:

Step-by-step explanation:

Answer:
(3,-3) (5,-3) (3,-6)
Step-by-step explanation:
I hope this helps!!
The segment marked 20 is the geometric mean of the two pieces into which it splits the hypotenuse. You get the proportion

Solving,

To find b, use the fact that b is the geometric mean of the whole hypotenuse, 21 + a, and the part that is attached to it, a.

A little arithmetic shows that

.
Answer: the first one
Step-by-step explanation: