Final answer:
To find the value of 'a' in the equation y = a(x+2)^2 - 15, substitute the coordinates (1,3) into the equation and solve for a. The calculated value of a is 2.
Step-by-step explanation:
The student is asking to find the value of a in the parabolic equation y = a(x+2)2 - 15 given that the parabola passes through the point (1,3). To find a, substitute x with 1 and y with 3 in the equation and solve for a.
First, plug in the coordinates:
3 = a(1+2)2 - 15
Next, simplify and solve the equation:
- 3 = a(3)2 - 15
- 3 = 9a - 15
- 18 = 9a
- a = 2
Therefore, the value of a is 2.