Answer:
C
Step-by-step explanation:
The circumference (C) of a circle = 2πr ← r is the radius
Given C = 15π the equating gives
2πr = 15π ( divide both sides by 2π )
r = = 7.5 cm
The area (A) of a circle is calculated using the formula
A = πr² = π × 7.5² = 56.25π cm² → C
Answer:
Step-by-step explanation:
The axis of symmetry can be calculated using the formula:
First we must determine a and b from the quadratic: . This is in standard form, with the highest power first in descending order.
Standard form is also:
If we compare this to the quadratic given, we can conclude that:
Substitute the values for a and b into the formula.
Multiply in the denominator.
Divide.
This can also be determined from the graph. It is the x-coordinate of the vertex or the maximum/minimum. It divides the quadratic into 2 symmetrical halves.
