solving equations

[terminator]

I'm being asked to solve 7sinx +2=5 (0 - 180 degrees) using a graph calculator Ti 83/plus

the book said to find the zeros (which I had found x=154.6 and y =0) but in the book the answer is x1 = 25.4 degres and x2 = 154.6 degrees).
I'm definitely doing something wrong/miss something.

please help.

 

[srmichael]

I'm being asked to solve 7sinx +2=5 (0 - 180 degrees) using a graph calculator Ti 83/plus

the book said to find the zeros (which I had found x=154.6 and y =0) but in the book the answer is x1 = 25.4 degres and x2 = 154.6 degrees).
I'm definitely doing something wrong/miss something.

please help.

It's hard to tell where your error is without seeing the steps you took to solve using your calculator. I can tell you that:

\(\displaystyle \displaystyle 7sin(x)+2=5\)

\(\displaystyle \displaystyle 7sin(x)=3\)

\(\displaystyle \displaystyle sin(x)=\frac{3}{7}\)

\(\displaystyle \displaystyle arcsin(\frac{3}{7})=25.4^{\circ}\)

Since you state they want all angles that satisfy this equation from 0 to 180 degrees, then the other answer would be 180-25.4 or 154.6 degrees.

 

[pappus]

I'm being asked to solve 7sinx +2=5 (0 - 180 degrees) using a graph calculator Ti 83/plus

the book said to find the zeros (which I had found x=154.6 and y =0) but in the book the answer is x1 = 25.4 degres and x2 = 154.6 degrees).
I'm definitely doing something wrong/miss something.

please help.

I'm not sure what you did but here is how I did it :

1. Switch your calculator into DEGREE-mode.

2. Draw the graph of

\(\displaystyle y = 7 \sin(x)-3\)

Keep in mind that the argument is in degree so you have to set the window accordingly.

3. Determine the zeros of the function using the CALC-menu of your calculator.