Answer:
sin²x = (1 - cos2x)/2 ⇒ proved down
Step-by-step explanation:
∵ sin²x = (sinx)(sinx) ⇒ add and subtract (cosx)(cosx)
(sinx)(sinx) + (cosx)(cosx) - (cosx)(cosx)
∵ (cosx)(cosx) - (sinx)(sinx) = cos(x + x) = cos2x
∴ - cos2x + cos²x = -cos2x + (1 - sin²x)
∴ 1 - cos2x - sin²x = (1 - cos2x)/2 ⇒ equality of the two sides
∴ (1 - cos2x) - 1/2(1 - cos2x) = sin²x
∴ 1/2(1 - cos2x) = sin²x
∴ sin²x = (1 - cos2x)/2
Answer:
x < - 2
Step-by-step explanation:
given - 4.9x + 1.3 > 11.1 ( subtract 1.3 from both sides )
- 4.9x > 9.8 ( divide both sides by - 4.9 )
Remembering to reverse the direction of the inequality symbol as a result of dividing by a negative quantity.
x < - 2 ← inequality reversed
solution set : x ∈ ( - ∞, - 2 )
C=2pir
area=pir^2
given
c=25.12
25.12=2pir
pi=3.14
25.12=2(3.14)r
25.12=6.28r
divide both sides by 6.25
4=r
sub into other
area=pir^2
area=pi4^2
area=16pi
area=16(3.14)
area=50.24
the area is 50.24 square cm
Answer:
2
Step-by-step explanation:
i hope it will help u hmm
Answer:
f(x) = -5x - 4
Step-by-step explanation:
We want to get the inverse of the following function:
f^-1(x) = (-1/5)x - 4/5
To do that, we have to replace x with f(x) and f^-1(x) with x, as follows:
x = (-1/5)f(x) - 4/5
And then solve for f(x), the inverse of f^-1(x).
x + 4/5 = (-1/5)f(x)
f(x) = -5x + (-5)4/5
f(x) = -5x - 4
To check our result we compute a pair (x, f(x))
x f(x)
1 -5*1 - 4 = -9
which has to be equivalent to (-9, 1) in the original function
x f^-1(x)
-9 (-1/5)*(-9) - 4/5 = 1
