- #1
roam
- 1,271
- 12
Hello! I need some help here please for ppl who are familiar with implicit differentiation.
Use implicit differentiation to find dy/dx, in each case say where it is defined;
a) [tex]y^5 +x^2 y^3 = 1+xy[/tex]
b) [tex]y= \frac{x^{3/2}\sqrt{7x^2 +1}}{sin(x) e^{3x^2 + 2x}}[/tex], [tex]x \neq n\pi [/tex] n [tex]\in[/tex] Z
3. The Attempt at a Solution
a) [tex]y^5 +x^2 y^3 = 1+xy[/tex]
[tex]5y^4+x^2 3y^2+2xy^3 \frac{dy}{dx} = x + y[/tex]
[tex]\frac{dy}{dx} = \frac{x+y}{5y^4 +x^2 3y^2 +2xy^3}[/tex]
Is that right? what does it mean "say where it is defined"?
b) [tex]y= \frac{x^{3/2}\sqrt{7x^2 +1}}{sin(x) e^{3x^2 + 2x}}[/tex]
we must use the quotient rule;
f = [tex]x^{3/2}\sqrt{7x^2 +1}[/tex]
f' = [tex]x^{3/2} . -\frac{14x}{-2\sqrt{7x^2 +1}}+ \sqrt{7x^2 +1} .\frac{2}{3}x^{1/2}[/tex] (using the product rule)
g = [tex]sin(x) e^{3x^2 + 2x}[/tex]
g' = [tex]sin(x).6x+2e^{3x^2 + 2x} + e^{3x^2 + 2x} . cos (x)[/tex] (using the product rule again)
[tex] \frac{sin(x) e^{3x^2 + 2x} . x^{3/2} . -\frac{14x}{-2\sqrt{7x^2 +1}}+ \sqrt{7x^2 +1} .\frac{2}{3}x^{1/2} - (x^{3/2}\sqrt{7x^2 +1}) . (sin(x).6x+2e^{3x^2 + 2x} + e^{3x^2 + 2x} . cos (x))}{(sin(x) e^{3x^2 + 2x})^2} [/tex]
Any suggestions on what I should do next? This looks very messy!
Use implicit differentiation to find dy/dx, in each case say where it is defined;
a) [tex]y^5 +x^2 y^3 = 1+xy[/tex]
b) [tex]y= \frac{x^{3/2}\sqrt{7x^2 +1}}{sin(x) e^{3x^2 + 2x}}[/tex], [tex]x \neq n\pi [/tex] n [tex]\in[/tex] Z
3. The Attempt at a Solution
a) [tex]y^5 +x^2 y^3 = 1+xy[/tex]
[tex]5y^4+x^2 3y^2+2xy^3 \frac{dy}{dx} = x + y[/tex]
[tex]\frac{dy}{dx} = \frac{x+y}{5y^4 +x^2 3y^2 +2xy^3}[/tex]
Is that right? what does it mean "say where it is defined"?
b) [tex]y= \frac{x^{3/2}\sqrt{7x^2 +1}}{sin(x) e^{3x^2 + 2x}}[/tex]
we must use the quotient rule;
f = [tex]x^{3/2}\sqrt{7x^2 +1}[/tex]
f' = [tex]x^{3/2} . -\frac{14x}{-2\sqrt{7x^2 +1}}+ \sqrt{7x^2 +1} .\frac{2}{3}x^{1/2}[/tex] (using the product rule)
g = [tex]sin(x) e^{3x^2 + 2x}[/tex]
g' = [tex]sin(x).6x+2e^{3x^2 + 2x} + e^{3x^2 + 2x} . cos (x)[/tex] (using the product rule again)
[tex] \frac{sin(x) e^{3x^2 + 2x} . x^{3/2} . -\frac{14x}{-2\sqrt{7x^2 +1}}+ \sqrt{7x^2 +1} .\frac{2}{3}x^{1/2} - (x^{3/2}\sqrt{7x^2 +1}) . (sin(x).6x+2e^{3x^2 + 2x} + e^{3x^2 + 2x} . cos (x))}{(sin(x) e^{3x^2 + 2x})^2} [/tex]
Any suggestions on what I should do next? This looks very messy!