Respuesta :
The answer is 252.5 ft
y = –0.004x² + x + 2.5
Let's take y = 0 and we'll get the quadratic equation:
–0.004x² + x + 2.5 = 0
The general formula for quadratic equation is:
ax² + bx + c = 0
a = -0.004
b = 1
c = 2.5
[tex]x_{1,2} = \frac{-b+/- \sqrt{ b^{2}-4ac} }{2a} =\frac{-1+/- \sqrt{ 1^{2}-4*(-0.004)*2.5} }{2*(-0.004)} = \frac{-1+/- \sqrt{1+0.04} }{-0.008} = \\ =\frac{-1+/- \sqrt{1.04} }{-0.008} = \frac{-1+/-1.02}{-0.008} [/tex]
[tex]x_1=\frac{-1+1.02}{-0.008} = \frac{0.02}{-0.008} = -2.5 \\ x_2=\frac{-1-1.02}{-0.008} = \frac{2.02}{-0.008} = 252.5[/tex]
Since distance cannot be negative (x1), the correct answer is x2 = 252.5 ft
y = –0.004x² + x + 2.5
Let's take y = 0 and we'll get the quadratic equation:
–0.004x² + x + 2.5 = 0
The general formula for quadratic equation is:
ax² + bx + c = 0
a = -0.004
b = 1
c = 2.5
[tex]x_{1,2} = \frac{-b+/- \sqrt{ b^{2}-4ac} }{2a} =\frac{-1+/- \sqrt{ 1^{2}-4*(-0.004)*2.5} }{2*(-0.004)} = \frac{-1+/- \sqrt{1+0.04} }{-0.008} = \\ =\frac{-1+/- \sqrt{1.04} }{-0.008} = \frac{-1+/-1.02}{-0.008} [/tex]
[tex]x_1=\frac{-1+1.02}{-0.008} = \frac{0.02}{-0.008} = -2.5 \\ x_2=\frac{-1-1.02}{-0.008} = \frac{2.02}{-0.008} = 252.5[/tex]
Since distance cannot be negative (x1), the correct answer is x2 = 252.5 ft