Hello luv! So here is how I will evaluate this expression
-4x+7, x=-1 so you are using substitution
-4(-1)+7
=11
:)
Answer:
Step-by-step explanation:
Please check below in the attached, you will see answer to given questions, thank you, I hope it helps.
Answer:
Step-by-step explanation:
It c just took the test
Use the formula A=p(1+r)^n
where
A= value of investment
r= rate
n= time period
p= amount invested
in this question
r= 5.75% but compounded quarterly means divide this by 4
r= 23/1600
n=7*4
n=28
p= $1200
A=1200(1+23/1600)^28
A= $1789.54
Therefore the value of her investment in 7 years is $1789.54
Answer:
0
Step-by-step explanation:
∫∫8xydA
converting to polar coordinates, x = rcosθ and y = rsinθ and dA = rdrdθ.
So,
∫∫8xydA = ∫∫8(rcosθ)(rsinθ)rdrdθ = ∫∫8r²(cosθsinθ)rdrdθ = ∫∫8r³(cosθsinθ)drdθ
So we integrate r from 0 to 9 and θ from 0 to 2π.
∫∫8r³(cosθsinθ)drdθ = 8∫[∫r³dr](cosθsinθ)dθ
= 8∫[r⁴/4]₀⁹(cosθsinθ)dθ
= 8∫[9⁴/4 - 0⁴/4](cosθsinθ)dθ
= 8[6561/4]∫(cosθsinθ)dθ
= 13122∫(cosθsinθ)dθ
Since sin2θ = 2sinθcosθ, sinθcosθ = (sin2θ)/2
Substituting this we have
13122∫(cosθsinθ)dθ = 13122∫(1/2)(sin2θ)dθ
= 13122/2[-cos2θ]/2 from 0 to 2π
13122/2[-cos2θ]/2 = 13122/4[-cos2(2π) - cos2(0)]
= -13122/4[cos4π - cos(0)]
= -13122/4[1 - 1]
= -13122/4 × 0
= 0
