How do you graph, find any intercepts, domain and range of f(x)=(1/4)^(x+4)-3f(x)=(14)x+43?

1 Answer
Dec 3, 2017

See below.

Explanation:

y axis intercept occurs when x=0x=0

y=(1/4)^(0+4)-3=1/256-3=color(blue)(-767/256)y=(14)0+43=12563=767256

x axis intercept occurs when y=0y=0

(1/4)^(x+4)-3=0(14)x+43=0

(1/4)^(x+4)=3(14)x+4=3

(x+4)ln(1/4)=ln3=>x=(ln3)/(ln(1/4))-4~~color(blue)(-4.792)(x+4)ln(14)=ln3x=ln3ln(14)44.792

There are no constraints on xx so domain is:

color(blue)({x in RR})

as x->oo , color(white)(888)(1/4)^(x+4)->0

So:

as x->oo , color(white)(888)(1/4)^(x+4)-3->-3

The line color(blue)(y=-3) color(white)(88) is a horizontal asymptote.

For x<-4

(1/4)^(x+4) becomes color(white)(888)1/((1/4)^(x+4))

So:

as x->-oo , color(white)(888)1/((1/4)^(x+4))->oo

and:

x->-oo , color(white)(888)1/((1/4)^(x+4))-3->oo

Range:

color(blue)({y in RR : -3 < y < oo })

Graph:

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