- Today we reconsidered the linear equation & the general form of a linear equation is y = mx + c
- where by the m refers to the GRADIENT
- where c is the Y-INTERCEPT (or the value of y when x = 0)
- m is POSITIVE when as x increases, y also increases
- m is NEGATIVE when as x increases, y will decrease
- m is ZERO when as x changes, y is constant (HORIZONTAL LINE)
- m is undefined when x is constant and y changes (VERTICAL LINE)
- X-INTERCEPT would be equal to -c / m ... (or the value of x when y = 0)
NOTE - c (or the constant in all the equation) is always the y-intercept, even for equations such as y = ax^2 + bx + c ...
Why do you think this is so? (HINT - look at point (3) above)
Prove point (8) for yourself ...
y=ax² + bx +c
ReplyDeleteat the y intercept
x=0
y=a(0)²+b(0)+c
= c
y intercept = (0.C)
C is not always the y intercept since if the it was 1/x, it would be undefined so c cannot be the y intercept
ReplyDeletey=1/x+4
=undefined