If f(x) = 3x^2 - 7 and g(x) = 2x + a, find a so that the graph of f(g(x)) crosses the y-axis at 68.
Follow Math Help Forum on Facebook and Google+
Originally Posted by blueridge If f(x) = 3x^2 - 7 and g(x) = 2x + a, find a so that the graph of f(g(x)) crosses the y-axis at 68. The y-intercept is when x=0. So when x=0 we have That means, Thus, Thus, Thus,
I'm curious, but what would be the answer if g(f(x)) crosses the x-axis at 68?
Originally Posted by blueridge I'm curious, but what would be the answer if g(f(x)) crosses the x-axis at 68? So you're trying to find: Since x = 68 First find g(f(x)):.. .. .. Since it crosses the x - axis at 68, the y coordinate is zero. is the same as the y coordinate:.. .. ..