How do you graph y=(x+5)/(2x-4) using asymptotes, intercepts, end behavior?

2 Answers
Dec 10, 2016

Asymptotes: uarr x = 2 darr and larr y = 1/2 rarr.y-intercept: 5/2. x-intercept : 2. (x, y) to (+-oo, 1/2) and (2, +-oo), in the opposite directions of the asymptotes y =1/2 and x = 2.

Explanation:

Cross multiplying and reorganizing,

(x-2)(y-1/2)=7/2# that represents a rectangular hyperbola (RH) having

asymptotes given by

x=2 and y=1/2.

The center of the RH is (2, 1/2).

y-intercept ( x = 0 ): 5/2

x-intercept ( y = 0 ):-5

(x, y) to (+-oo, 1/2) and (2, +-oo), in the opposite directions of the

asymptotes y = 1/2 and x = 2, respectively.

graph{y(2x-4)-x-5=0 [-10, 10, -5, 5]}

Dec 10, 2016

See explanation.

Explanation:

A vertical asymptote occurs at x-values that make the denominator 0. To find the vertical asymptote(s) (V.A.'s), set your denominator equal to zero and solve for x:

V.A. when 2x-4=0
<=>2x=4
<=>x=2

So the equation for the V.A. is x=2.

A horizontal asymptote occurs when the degree of the numerator is less than (or equal to) the degree of the denominator. ("Degree" means the highest power of x.) Since both sides of the fraction have a degree of 1, there will be a horizontal asymptote.

When the degrees are the same (like in this case), the horizontal asymptote is found at y=the ratio of the leading coefficients. Here, that happens to be y=1/2 (from (color(red)1x+5)/(color(red)2x-4)).

(In the case that the denominator has a higher degree, the asymptote is always y=0.)

The x-intercept is found by letting y=0 and solving for x:

0=(x+5)/(2x-4)

0=x+5 [multiply both sides by (2x-4) ]

x="-5"

So our x-intercept is at ("-5",0).

Similarly, the y-intercept is found by letting x=0 and solving for y:

y=((0)+5)/(2(0)-4)

y=5/"-4"=-5/4

So our y-intercept is at (0,-5/4).

With all this information, we can now draw our hyperbola:

graph{(y-(x+5)/(2x-4))(y-(x-2.0001)/(2x-4))=0 [-8.835, 11.165, -3.91, 6.09]}