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
The answer for Group A. is 0.080 or 0.08
the answer for Group B. 1.07 or 1.070
Answer:
2x + 3y = 12
Step-by-step explanation:
Standard form is Ax + By = C, A, B and C must be intergers, cannot be fractions or decimals
y = -2/3x + 4 First we want to get rid of the fractions. There is only one, so if we multiply both sides by 3 that should do it.
3y = -2x + 12 Now make the constant be on one side by itself
2x + 3y = 12
