SOLUTION: Find dy/dx x=7sint y=14cost dx/dt:7cos dy/dt-14sin or 14-sin (I'm not sure) dy/dx=2-tan or -2tan (dunno which one0 (which is incorrect) pls help clarify why?) x=e^9t

Algebra ->  Trigonometry-basics -> SOLUTION: Find dy/dx x=7sint y=14cost dx/dt:7cos dy/dt-14sin or 14-sin (I'm not sure) dy/dx=2-tan or -2tan (dunno which one0 (which is incorrect) pls help clarify why?) x=e^9t       Log On


   



Question 885297: Find dy/dx
x=7sint
y=14cost
dx/dt:7cos
dy/dt-14sin or 14-sin (I'm not sure)
dy/dx=2-tan or -2tan (dunno which one0 (which is incorrect) pls help clarify why?)
x=e^9t
y=18t
dx/dt=9e^9t
dy/dx=18
dy/dx=18/9e^9t (which is wrong again, please tell me what I am doing wrong)
thank you
thank you

Answer by rothauserc(4718) About Me  (Show Source):
You can put this solution on YOUR website!
1) x = 7sin(t)
dx/dt = 7cos(t)
2) y = 14cos(t)
dy/dt = -14sin(t)
3) dy/dx = (dy/dt) / dx/dt) = -14sin(t) / 7cos(t) = -2tan(t)
4) x=e^(9t)
let u = 9t
d/dt[e^u] = e^(9t) * u'
d/dt[e^u] = e^(9t) * 9
d/dt[e^u] = 9e^(9t)
5) y=18t
dy/dt = 18
6) dy/dx = (dy/dt) / dx/dt) = 18 / 9e^(9t) = 2e(-9t)