I believe the answer to this diagram should be <u><em>Diagram B</em></u>
If the discount is 15 percent, he still pays (100-15) or 85%
125.99 * 85%
125.99 * .85 = 107.09 is the price he pays for the rod
107.09 * .03 =3.21 is the sales tax
107.09+3.21=110.30 is the price of the rod with the discount and the tax
Answer:
x1, x2 = 4.74 , -2.74
Step-by-step explanation:
To find the roots of a quadratic function we have to use the bhaskara formula
ax^2 + bx + c
x^2 - 2x - 13
a = 1 b = -2 c = -13
x1 = (-b + √ b^2 - 4ac)/2a
x2 =(-b - √ b^2 - 4ac)/2a
x1 = (2 + √ (2^2 - 4 * 1 * (-13)))/2 * 1
x1 = (2 + √ (4 + 52)) / 2
x1 = (2 + √ 56 ) / 2
x1 = (2 + 7.48) / 2
x1 = 9.48 / 2
x1 = 4.74
x2 = (2 - √ (2^2 - 4 * 1 * (-13)))/2 * 1
x2 = (2 - √ (4 + 52)) / 2
x2 = (2 - √ 56 ) / 2
x2 = (2 - 7.48) / 2
x2 = -5.48 / 2
x2 = -2.74
235.24 + 45.58 = 280.82
280.82/2 = 140.41
each check was for $140.41
THe amplitude is half of the distance from the highest and lowest phase of the wave..
4-(-1)=5
0.5*5=2.5
amp=2.5 units
