## Sytee 2 years ago How to solve this? A curve has an equation y=2/x^2 + 5/2 Find the equation of the tangent to the curve at point (2,3)

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1. Decart

$\frac{ 2 }{x ^{2} }+\frac{ 5 }{ 2 }$

2. Sytee

what did u just wrote, it became error. all of a sudden

3. Decart

is that the equation

4. Decart

do you need to take the derivative

5. Peter14

|dw:1384947669567:dw|

6. Peter14

is the equation, right?

7. Sytee

@Peter14 yes that is the equation

8. Sytee

@Decart yes,need to take the derivative , how?

9. Decart

quotient rule

10. Sytee

i get dy/dx = -4x^-3, after that what should i do?

11. Peter14

or simplify it to 2x^(-2)

12. Decart

the low times the derivative of the high - the high times the derivative of the low all divided by the low squared

13. Peter14

do you know point-slope form?

14. Sytee

no

15. Decart

once you find the derivative that gives you the slope

16. Decart

the derivative is $\frac{ 4 }{ x ^{3} }$

17. Decart

plug in the x to get the slope

18. Peter14

with a point (x1, y1) and a slope m the equation of a line can be written (y-y1)=m(x-x1)

19. Sytee

1/2 is m ?

20. Decart

yes

21. Decart

y-3=1/2(x-2)

22. Decart

distribute the 1/2 and then add the three

23. Sytee

i got it!!! i have another question

24. Sytee

solve the equation 3 cos 2x + 5 sinx =4 for 0 <x<360

25. Peter14

you have to simplify it first, use the identity for cos 2x

26. Sytee

how to simplify that?

27. Peter14

use the identity for cos 2x