Algebraically Solving Trig Functions for T: Tips and Tricks

  • Thread starter Thread starter gjb19
  • Start date Start date
  • Tags Tags
    Trig
Click For Summary
To solve the equations y = 20 sin(π/15 t) + 25 and y = -10cos(2π/15 t) + 12 algebraically for T, start by setting them equal to each other. Utilize the double-angle formula for cosine, rewriting -10cos(2π/15 t) as -10(cos²(π/15 t) - sin²(π/15 t)). This allows the equation to be expressed in terms of sine and cosine, facilitating the application of the quadratic formula. Simplifying the resulting expression will lead to a solvable quadratic equation for T. This method effectively combines trigonometric identities with algebraic techniques to find the solution.
gjb19
Messages
2
Reaction score
0
Ok, we'll basically we have two different functions and we're told to set them equal and then algebracially solve them for T.

Here are the functions:

y = 20 sin(pie/15 t) + 25

y = -10cos(2pie/15 t) + 12

It gives a hint and says to use a double-angle forumla and the quadratic forumla to help if needed.

Does anyone have any idea on where to start? I'm totally confused.

Thanks a lot!
 
Physics news on Phys.org
y = -10Cos(2pi/15 t) + 12
y = -10({Cos(pi/15t)}^2 - {Sin(pi/15t)}^2) + 12

From here it is pretty obvious what to do, get the expression in terms of Sin and solve for Y.
 

Similar threads

  • · Replies 9 ·
Replies
9
Views
2K
Replies
7
Views
2K
Replies
7
Views
8K
  • · Replies 2 ·
Replies
2
Views
2K
  • · Replies 1 ·
Replies
1
Views
2K
Replies
11
Views
35K
  • · Replies 3 ·
Replies
3
Views
10K
Replies
1
Views
1K
Replies
11
Views
6K
  • · Replies 2 ·
Replies
2
Views
3K