Volume of cone: pi * r^2 * h/3
Given volume, height
942in^3 = 3.14 * r^2 * 9/3
942in^2 = r^2 * 9.42
Divide by 9.42
r^2 = 100, r = -10, 10
Cannot be negative so...
Solution: radius is 10 in.
Answer: (3x + 11y)^2
Demonstration:
The polynomial is a perfect square trinomial, because:
1) √ [9x^2] = 3x
2) √121y^2] = 11y
3) 66xy = 2 *(3x)(11y)
Then it is factored as a square binomial, being the factored expression:
[ 3x + 11y]^2
Now you can verify working backwar, i.e expanding the parenthesis.
Remember that the expansion of a square binomial is:
- square of the first term => (3x)^2 = 9x^2
- double product of first term times second term =>2 (3x)(11y) = 66xy
- square of the second term => (11y)^2 = 121y^2
=> [3x + 11y]^2 = 9x^2 + 66xy + 121y^2, which is the original polynomial.
Answer:
mDF = 90°
(Assuming arc mCE is 5x + 10)
Step-by-step explanation:
When we have two chords crossing in a circle, there is a property where the angle in the cross point is equal half the sum of the corresponding arcs.
So in this case, we have:
70° = (mCE + mDF)/2
Assuming mCE is 5x + 10, we have:
70 = (5x + 10 + 11x + 2)/2
70 = (16x + 12)/2
70 = 8x + 6
8x = 64
x = 8
So the arc mDF is:
mDF = 11x + 2 = 11 * 8 + 2 = 90°
