`y=(x-1)/(x+5)`
First, determine the vertical asymptote of the rational function. Take note that vertical asymptote refers to the values of x that make the function undefined. Since it is undefined when the denominator is zero, to find the VA, set the denominator equal to zero.
`x+5=0`
`x=-5`
Graph this vertical asymptote on the grid. Its graph should be a dashed line. (See attachment.)
Next, determine the horizontal or slant asymptote. To do so, compare the degree of numerator and denominator.
degree of numerator = 1
degree of the denominator = 1
Since they have the same degree, the asymptote is horizontal. To get the equation of HA, divide the leading coefficient of numerator by the leading coefficient of the denominator.
`y=1/1`
`y=1`
Graph this horizontal asymptote on the grid. Its graph should be a dashed line.(See attachment.)
Next, find the intercepts.
y-intercept:
`y=(0-1)/(0+5)`
`y=-1/5`
So the y-intercept is `(0, -1/5)` .
x-intercept:
`0=(x-1)/(x+5)`
`(x+5)*0=(x-1)/(x+5)*(x+5)`
`0=x-1`
`1=x`
So, the x-intercept is `(1,0)` .
Also, determine the other points of the function. To do so, assign any values to x, except -5. And solve for the y values.
`x=-15, y=(-15-1)/(-15+5) = (-16)/(-10)=8/5`
`x=-11, y=(-11-1)/(-11+5)=(-12)/(-6)=2`
`x=-7, y=(-7-1)/(-7+5)=(-8)/(-2)=4`
`x=-6, y=(-6-1)/(-6+5)=(-7)/(-1)=7`
`x=-3, y=(-3-1)/(-3+5) = (-4)/2=-2`
`x=4, y=(4-1)/(4+5)=3/9`
`x=15, y=(15-1)/(15+5)=14/20=7/10`
Then, plot the points `(-15,8/5)` , `(-11,2)` , `(-7,4)` , `(-6,7)` , `(-3,-2)` , `(0,-1/5)` , `(1,0)` , `(4,3/9)` and `(15,7/10)` .
And connect them.
Therefore, the graph of the function is:
Base on the graph, the domain of the function is `(-oo, -5) uu (-5,oo)` . And its range is `(-oo, 1) uu (1,oo)` .
No comments:
Post a Comment