# Thread: Continuity of hybrid functions.

1. ## Continuity of hybrid functions.

Final is tomorrow brahs....I NEED an A.

I just Don't understand the steps to solving these, please show step by step what you do.

For this last one I get 5sin^4 (x^3 +3)+sin^5 (3x^2)

But he says the right answer is: 5sin^4 (x^3)cos(x^3 +3)(3x^2)

Where do you get that cos?

3. ## Re: Need some Calc 1 Help PLEASE!

Originally Posted by pickslides
http://i200.photobucket.com/albums/a...725_181552.jpg

http://i200.photobucket.com/albums/a...725_181609.jpg

http://i200.photobucket.com/albums/a...725_185540.jpg

I just thought showing you direct pictures of the questions would be easier for someone to understand.

Please tell me if these links do not work and i can just write down the questions

4. ## Re: Need some Calc 1 Help PLEASE!

Originally Posted by Bespetna

Please tell me if these links do not work and i can just write down the questions
It's always best to write down the questions here.

Be sure to show your workings and where you are stuck.

5. ## Re: Need some Calc 1 Help PLEASE!

1) Let f(x)=A^2 X^2, X <or equal to 2
(1-A)x, x>2

For what values of A is f continuous at X=2

2) Is the following function continuous at X=3?
Redefine it so that it is continuous? Let
f(x) = (x^2-x-6)/(x-3) X does not equal 3
8 x=3

6. ## Re: Need some Calc 1 Help PLEASE!

3)
Find the derivative of f(x)=sin^5 (x^3+3)

For this last one I get 5sin^4 (x^3 +3)+sin^5 (3x^2)

But he says the right answer is: 5sin^4 (x^3)cos(x^3 +3)(3x^2)

7. ## Re: Need some Calc 1 Help PLEASE!

Originally Posted by Bespetna
1) Let f(x)=A^2 X^2, X <or equal to 2
(1-A)x, x>2
The first function is a parabola and the second a linear function, the entire function will be continuous at x=2 if they are equal there.

So solve $a^2\times 2^2 = (1-a)\times 2$

Originally Posted by Bespetna
2) Is the following function continuous at X=3?
Redefine it so that it is continuous? Let
f(x) = (x^2-x-6)/(x-3) X does not equal 3
8 x=3
Factor the numerator, what do you get?

8. ## Re: Need some Calc 1 Help PLEASE!

Originally Posted by Bespetna
Final is tomorrow brahs....I NEED an A.

I just Don't understand the steps to solving these, please show step by step what you do.

For this last one I get 5sin^4 (x^3 +3)+sin^5 (3x^2)

But he says the right answer is: 5sin^4 (x^3)cos(x^3 +3)(3x^2)

Where do you get that cos?

2) $\lim_{x\to2^-}f(x)=\lim_{x\to2^+}f(x)=f(2)$

3) Answer to this question: Is $\lim_{x\to 3^-}f(x)=\lim_{x\to 3^+}f(x)=f(3)$?

If the answer is not. Replace the 8 with other number. (Which?)

1) $f(x)=\sin^5(x^3+3)$

$f'(x)=5\sin^4(x^3+3)\cos(x^3+3)\cdot 3x^2=15x^2\sin^4(x^3+3)\cos(x^3+3)$