Just take 78 and divide by 3, he gets 26 mpg with his car.
The value of cos 4x from the given identity is 0.999
<h3>Trigonometry identity</h3>
Given the cosine identity
cos8x = 13/36
Determine the value of x
8x = arccos(13/36)
8x = 0.36111
x = 0.36111/8
x = 0.04514
Determine the value of cos4x
cos4x = cos4(0.04514)
cos4(0.04514) = 0.999
Hence the value of cos 4x from the given identity is 0.999
Learn more trig identity here; brainly.com/question/7331447
Answer:
(A)
Length of DE = √17
EF = √18
DF = √17
(B) Slope of DE = 4
EF = 1
DF = 1/4
(C) Isosceles triangle.
Step-by-step explanation:
See attached image.