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:
10.4 miles
Step-by-step explanation:
Write an equation for the total cost paid as a function of the # of miles driven:
L(x) = $6.75 + ($3.20/mile)x
and set this equal to $40.03 to determine the # of miles Lupita rode:
L(x) = $6.75 + ($3.20/mile)x = $40.03
Isolate the x term by subtracting $6.75 from both sides:
($3.20/mile)x = $40.03 - $6.75 = $33.28
Finally, divide both sides by ($3.20/mile):
x = $33.28 / ($3.20/mile)
= 10.4 miles
Lupita rode 10.4 miles in the taxi.
For the functions f(x) = 4x + 7 and g(x) = -9x + 11, find f(g(0)). For the functions f(x) = 3x2 - 7 and g(x) = -3x2 + 4, find f(g(2)). (Do NOT put commas in large numbers.)
