prove that, g(a2)= g(a-2)
Answers
Answer:
Three points are needed on the parabola
x = 0, y = 20
x = -600, y = 170
x = +600, y = 170
using the form ax^2 + bx + c = y, we know that c=20
x=-600, y = 170 and x =+600, y = 170; write two equations
-600^2a - 600b + 20 = 170
+600^2a + 600 + 20 = 170
use elimination
360000a - 600b + 20 = 170
360000a + 600b + 20 = 170
------------------------------addition eliminates b
720000a + 40 = 340
720000a = 300
a = 300/720000
a = .0004167
Now we can write the equation
y = .0004167x^2 + 20
Graphically
+graph%28+300%2C+200%2C+-700%2C+700%2C+-100%2C+200%2C+.0004167x%5E2%2B20%2C+170%2C+116%29+
:
"How high is the cable 120m away from a tower? "
600 - 120 = 480
Solve for x=480
y = .0004167(480^2) + 20
y = 96 + 20
y = 116 m high (blue line)
Step-by-step explanation: