compute lim x^2+3x-10/ x-2
x--2
How would I compute this limit?

Question

compute lim      x^2+3x-10/ x-2 
              x-->2
How would I compute this limit?

anonymous · Answer

First step: Factor the polynomial in the numerator of the fraction.

anonymous · Answer

lol can you explain how to do that?

anonymous · Answer

You should have learned factoring polynomials a long, long time before ever learning limits. I would recommend practicing factoring polynomials on Khan Academy for a while until you are very comfortable with it.

In this case, you want to look for two numbers that multiply to -10 and sum to 3. The numbers in this example will be 5 and -2. So, you can factor the polynomial into (x+5)(x-2). The (x-2) terms then cancel, and you're left with $$\lim_{x\to2}x+5$$

anonymous · Answer

ohhhhhh ok i know how to that hold on let me try to work it

anonymous · Answer

ok i got 7

anonymous · Answer

Yes, that is the correct answer. Again, though, you should go get comfortable with factoring polynomials before you try to go any further with limits.

anonymous · Answer

no no im good with them i really know how to do that i just didn't know what it was called

anonymous · Answer

but I have one more question for you are you good with derivatives? i understand them but this has me confused

anonymous · Answer

y=e^9x^3+4x

anonymous · Answer

$$y=e^{9x ^{3}+4x}$$

anonymous · Answer

Just use the chain rule :)