# Math Help - True/False graphs

1. ## True/False graphs

Answer the following either true or false and justify your answer. Give an example if the statement is false and provide an explaination if true:

1) The graph of y=-4x^2+8 is obtained from the graph of x^2 by applying a vertical stretch, a reflection and a horizontal shift.

2.) If f(x)>0 for all x and g(x) is a vertical stretch of f(x) and g(x)>f(x), for all x

3.) Every linear function has a y-intercept

4.) The line through the points (1, -3) and (-2, 6) is perpindicular to the line with equation 6y-2x=0

Can anyone help me with these four questions..><.thank you

2. k i am not just gunna tell you what the answer are but i think i can help you find them.
1) A vertical strech, vertical being the y valus strech meaning increase, a reflection is flipping the graph about an axis, and a horizontial shift is shifting the graph left or right.
2) if f(x) is bigger then 0 and g(x) is just f(x) stretched about the vertical axis is G(x) always bigger then F(x)?
3) i really dont think so... but i have the slightest idea how to graph a linear function
maybe someone else can exsplain for the both of us?

3. Originally Posted by lemontea
3.) Every linear function has a y-intercept

4.) The line through the points (1, -3) and (-2, 6) is perpindicular to the line with equation 6y-2x=0
3) The general form of a linear function is $y = mx + b$. The y-intercept is defined to be the point on the function where x = 0. Is there a y-value for this point for every linear function?

4) Two lines are perpendicular if their slopes obey the equation $m_2 = -\frac{1}{m_1}$.

-Dan