Answer:
1.) 471.24
2.) 1231.5
3.) 113.1
Step-by-step explanation: A = pi x r^2 + pi x r x ^2
1.) a = 3.14 x (5)^2 + 3.14 x 5 x ^2
a = 3.14 x 25 + 3.14 x 5 x 25
a = 78.54 + 392.70
a ≈ 471.24
2.) A = 3.14 (7)^2 + 3.14 x (7) x ^2
a = 3.14 x 49 + 3.14 x 7 x 49
a = 153.93 + 1077.57
a ≈ 1231.5
3.) a = 3.14 (3)^2 + 3.14 x 3 x ^2
a = 3.14 x 9 + 3.14 x 3 x 9
a = 28.27 + 84.82
a ≈ 113.1
<span>B. sam forgot to multiply.
The correct answer is
</span> x^2*y=(7^<span>2)*(9)=49*9=441 </span>
Using the dot product:
For any vector x, we have
||x|| = √(x • x)
This means that
||w|| = √(w • w)
… = √((u + z) • (u + z))
… = √((u • u) + (u • z) + (z • u) + (z • z))
… = √(||u||² + 2 (u • z) + ||z||²)
We have
u = ⟨2, 12⟩ ⇒ ||u|| = √(2² + 12²) = 2√37
z = ⟨-7, 5⟩ ⇒ ||z|| = √((-7)² + 5²) = √74
u • z = ⟨2, 12⟩ • ⟨-7, 5⟩ = -14 + 60 = 46
and so
||w|| = √((2√37)² + 2•46 + (√74)²)
… = √(4•37 + 2•46 + 74)
… = √314 ≈ 17.720
Alternatively, without mentioning the dot product,
w = u + z = ⟨2, 12⟩ + ⟨-7, 5⟩ = ⟨-5, 17⟩
and so
||w|| = √((-5)² + 17²) = √314 ≈ 17.720
It all depends on the importance of the variable its self. Its important to solve it so you know what the variable is and its important to solve one at a time because its impossible to solve a variable completely if you have two of them
