We will use double angle identities:
cos (5x ) = sin (10x )
cos (5x ) = 2 cos (5x ) sin ( 5x )
cos ( 5 x) - 2 cos ( 5 x ) sin ( 5x ) = 0
cos ( 5 x ) · [ 1 - 2 sin (5 x) ] = 0
cos ( 5 x ) = 0 or : 1 - 2 sin (5 x) = 0
5 x = π/2 +kπ, k∈Z sin (5 x) = 1/2
x1 = π/10 + kπ/5 5 x = π/6+2kπ , k∈ Z
5 x = 5π/6 +2kπ , k∈ Z
x 2 = π/30 +2kπ/5
x 3 = π/9 + 2kπ/5
Answer:
We can't prove this with the SAS postulate.
Step-by-step explanation:
SAS means that two sides and the angle between those two sides are equal.
Side Angle Side (SAS)
That's why we can't prove this with the SAS postulate.
11
125
85
------
210
2
---------
420
3
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$12.50
Please include the inequality
