Answer: 0.4693877
Step-by-step explanation:
Given that:
cos x=−6/7,
From trigonometry :
Cosx + sinx = 1
Cos2x = cos(x + x)
Recall the double angle identity:
Cos2x = 2cos^2x - 1
Sin2x = 1 - 2sin^2x
Since cosx = - 6/7
Then
Cos2x = 2cos^2x - 1
Cos2x = 2cosx^2 - 1
Cos2x = 2(-6/7)^2 - 1
Cos2x = 2(36/49) - 1
Cos2x = 2 * (72/98) - 1
Cos2x = (2 * 0.7346938) - 1
Cos 2x = ( 1.4693877 - 1)
Cos2x = 0.4693877
Option A, because you split the (2x + 3) into 2x and 3.
19/5=p/3-36/5
Convert the decimals into fractions
15 x 19/5=(p/3-36/5) x 15
Multiply both sides by 15
57=5x-108
5x-108+108=57+108
Add 108 to both sides
5x=165
X=33
Answer
Hope this helps
9 if your in k12 this is the answer trust me i just took the test