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:
¼ x 20 = 5
⅛ x 56 = 7
0.16 x 32 = 5.12
4.5 x 9.1 = 40.95
Step-by-step explanation:
The answer to the first question is b
I don’t know the answer to the second one sorry
Answer:
12
Step-by-step explanation:
side 1: 4
side 2: 6
6*4*(1/2)
12
Answer:
Step-by-step explanation:
If you can present a problem in Latex, you can do anything. I don't know what the question mark is for. I'm just ignoring it.
55 2/3 * 66 5/6
One of the ways to get the answer is to use decimals
55.666666667 * 66.833333333 = 3720.38889
Another way to do this problem is to break up one of the numbers
55 2/3 (66 + 5/6) You can do this if you know how to use the distributive property.
55 2/3 * 66 + 55 2/3 * 5/6
( (165 + 2) / 3) * 66 + (165 + 2)/3 * 5/6
167/3 * 66 + 167 / 3 * 5/6
167 * 22 + (167 * 5 / (3 * 6)
3674 + 835 / 18
3674 + 46 7/18
3720 7/18
If none of these seem right and you have choices, please list them.
