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:
D) 11
Step-by-step explanation:
If you start at five and count back on each little x
than you should come up with 11
0=3
1=1
2=2
3=4
4=1
3+1+2+4+1=11
You do This because you need to find how many has fewer so you don't count 5
Answer:
36 will be the measure.
Hope it helps!!!
Step-by-step explanation:
Answer:
The ordered pair to represent a in the equation a=2b+c if b=(6,3) and c=(-4,8) is: a=(8,14)
Step-by-step explanation:
b=(6,3)
c=(-4,8)
a=2b+c
Replacing b and c in the equation above:
a=2(6,3)+(-4,8)
Multiplying:
a=(2*6,2*3)+(-4,8)
a=(12,6)+(-4,8)
Adding:
a=(12+(-4),6+8)
a=(12-4,14)
a=(8,14)