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
Answer:
X = 8, Y = 8
Step-by-step explanation:
Step 1) Solve for Y w/ bottom equation to yield - y = -2/3x + 40/3.
Step 2) substitute equation into x + y = 16 to get 1/3x + 40/3 = 16 multiply by 3 to clear the fractions and get x + 40 = 48 - subtract 40 by both sides to get x = 8.
Step 3) Plug x = 8 into the bottom equation to get 48 + 9y = 120, subtract 48 by both sides to get 9y = 72 and then divide by 9. The product is y = 8.
Put your hands on your head and breath while doing that walk around slowly until you feel cooled down
30)
10 x 6 = 60
11 x 4 = 44
12 x 4 = 48
60 + 44 + 48 = 152 cm^2
answer: area = 152 cm^2
I think it is 1/2
hope this helped