Answer:
(1-cos2A) /(1+cos2A) =tan²A
Proof:
We know that,
cos(A+B) =cosA.cosB-sinA.sinB
=>cos2A=cos(A+A)
=>cos2A=cosA.cosA - sinA.sinA
=>cos2A=cos²A-sin²A
=>cos2A=(cos²A-sin²A)/(cos²A+sin²A
Since {cos²A+sin²A=1}
Divide the numerator & the denominator by (cos²A) to get,
cos2A = {(cos²A-sin²A) ÷cos²A} / {(cos²A+sin²A) ÷cos²A}
cos2A ={(1-tan²A)/(1+tan²A)}
Then,
1-cos2A = 1-[{(1–tan²A)/(1+tan²A)}]
1-cos2A =(1+tan²A-1+tan²A)/(1+tan²A)
1-cos2A=(2tan²A)/(1+tan²A)
And now.......
1+cos2A=1+[{(1-tan²A)/(1+tan²A)}]
1+cos2A={1+tan²A+1-tan²A}/{1+tan²A}
1+cos2A=2/(1+tan²A)
So now,
(1-cos2A)/(1+cos2A)= {2tan²A/(1+tan²A)}÷{2/(1+tan²A)}
={(2tan²A)(1+tan²A)}÷{2(1+tan²A)}
=tan²A
Step-by-step explanation:
make me as brain liest
Answer: x = 3
Step-by-step explanation:
First you need to start by adding positive 4x to both sides since the 4x is a negative. 4x + (-7x) = -3x. Then it is just simply -3x+2 = -7. Since 2 is a positive number subtract both both sides by 2. Then you should get -3x = -9. Then divide both sides by -3 and the answer is x = 3.
Answer:
1,492,533
Step-by-step explanation:
Simple math
Answer:
y = 2x − 1
Step-by-step explanation:
By eliminating the parameter, first solve for t:
x = 4 + ln(t)
x − 4 = ln(t)
e^(x − 4) = t
Substitute:
y = t² + 6
y = (e^(x − 4))² + 6
y = e^(2x − 8) + 6
Taking derivative using chain rule:
dy/dx = e^(2x − 8) (2)
dy/dx = 2 e^(2x − 8)
Evaluating at x = 4:
dy/dx = 2 e^(8 − 8)
dy/dx = 2
Writing equation of line using point-slope form:
y − 7 = 2 (x − 4)
y = 2x − 1
Now, without eliminating the parameter, take derivative with respect to t:
x = 4 + ln(t)
dx/dt = 1/t
y = t² + 6
dy/dt = 2t
Finding dy/dx:
dy/dx = (dy/dt) / (dx/dt)
dy/dx = (2t) / (1/t)
dy/dx = 2t²
At the point (4, 7), t = 1. Evaluating the derivative:
dy/dx = 2(1)²
dy/dx = 2
Writing equation of line using point-slope form:
y − 7 = 2 (x − 4)
y = 2x − 1
Answer:
a. rad27
Step-by-step explanation:
we can use a2+b2=c2 where c is the hypotonuse.
we plug in 3^2+b2=6^2
9+b^2=36
b^2=27
then do a rad over each to get rid of the ^2 on the b
b=rad 27
answer is rad27
