Answer:
D. Pythagorean
Step-by-step explanation:
Given the identity
cos²x - sin²x = 2 cos²x - 1.
To show that the identity is true, we need to show that the left hand side is equal to right hand side or vice versa.
Starting from the left hand side
cos²x - sin²x ... 1
According to Pythagoras theorem, we know that x²+y² = r² in a right angled triangle. Coverting this to polar form, we have:
x = rcostheta
y = rsintheta
Substituting into the Pythagoras firnuka we have
(rcostheta)²+(rsintheta)² = r²
r²cos²theta+r²sin²theta = r²
r²(cos²theta+sin²theta) = r²
(cos²theta+sin²theta) = 1
sin²theta = 1 - cos²theta
sin²x = 1-cos²x ... 2
Substituting equation 2 into 1 we have;
= cos²x-(1-cos²x)
= cos²x-1+cos²x
= 2cos²x-1 (RHS)
This shows that cos²x -sin²x = 2cos²x-1 with the aid of PYTHAGORAS THEOREM
35 were not guppies.
Explanation:
63/9=7
7*4=28
63-28=35
Answer:

Step-by-step explanation:
Let
x ------> the number of dogs Larry walked
y -----> the number of dogs Kyle walked
we know that
The linear equation that represent this scenario is equal to

Answer:
B.
<h3>step by step explanation</h3>
I hope it's help
perimeter or rectangle= 2l+2w
Surface area of a cylinder=2(pi)r^2+2(pi)r
Volume of a triangular prism=Bh
Area of a circle=(pi)r^2