Posted by Gabe on .
test using the lead coefficient to find out if y arrow oo, or
y arrowoo as x arrow oo
y=5x^3+4x^2+6x7
n is odd 5x^3
an<0 5x^3
y arrow oo as x arrow oo
Is this right or do I need to go back and try again??????

coefficient 
Anonymous,
As x goes to infinity the only term that matter is 5x^3. As x^3 goes to negative infinity what does is it's sign? If you can't picture it than try separating negative infinity into 1(∞). Then cube it: (1(∞))^3 which becomes 1(∞)^3 because 1 cubed is still 1. Then what is infinity cubed? Still infinity right? So (1(∞))^3 is negative infinity. However there's the coefficient to take into account. The negative coefficient will change negative infinity to infinity. So y goes to infinity as x goes to infinity.