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:
n<50
Step-by-step explanation:
7/2*5n + 14<49
7n/2*5+14<49
(7n)+(2*5)14/2*5 <49
7n+10*14/2*5 <49
7n+140/2*5 <49
7n+140/10 <49
7n+140 < 10*49
7n+140 < 490
(7n+140)+(-140)<490+(-140)
7n+140-140<490-140
7n<350
7n/7 < 350/7
n<2*5^2*7/7
n<2*5^2
n<2*25
n<50
It will take him 80 minutes, or an hour and 20 minutes
Answer:
24
Step-by-step explanation:
Answer:
A. Positive Exponent
B. Negative Exponent
C. Rational Exponent
Step-by-step explanation:
» Any fraction is a rational exponent.
» If n is not zero, it can be negative or positive value. Then the exponent can be negative or positive.
