[stewartlindsay]

Show that the equation of the tangent to the curve y=x3-x2 at the point where x= -1 is y=5x+3

[galactus]

I assume you're in a claculus class. By now, you should know to use proper syntax.

What is this?: y=x3-x2.

That is what the ^(SHIFT 6) key is for.

Find the derivative of y and use x=-1 to find the slope at that point. It should be 5



After all, that is what a derivative does. Then, use y=mx+b and your given points , (-1,y(-1)), to find the tangent line equation. Just plug in x, y, and m and solve for b. That's it.

[Unknown008]

Do you know of 'Garbage In Garbage Out'? It's a computer term. If you make the wrong input, it's obvious that you will have a wrong output. So, if you want proper help, try making a minimum of efforts.

[g13544055]

the person might not know of the purpose of '^'. A lot of people don't use computers, and therefore wouldn't know the syntax.. Sir andrew wiles is one example. Pay no attention to them Stewart :)

[Unknown008]

That's why we are telling him how to do it! So that next time, he may make a better input!

[g13544055]

There are nicer ways to go about informing people.

"I assume you're in a claculus class. By now, you should know to use proper syntax.

What is this?: y=x3-x2."

Is not one of them, it's patronising and rude.

[Unknown008]

Well, I guess each one of us has his/her own personality and his/her own way to tell things, so long as the intention is the same.

[g13544055]

That's perfect rationalisation. Sarcasm.

I just hope you aren't in a position of national power.

[Unknown008]

Hmm, I'm 17 by the way... so no worries about it.

[g13544055]

I'll leave it at that then, won't continue with this. For 17 your level of maths is very good.

[Unknown008]

I'll take it as a compliment, thanks! :)