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Inverse Trigonometric Problem Solve equation for x

  • Thread starter chapsticks
  • Start date
1. The problem statement, all variables and given/known data

arctan(8x-8)=-1

2. Relevant equations

I'm sure what this part wants.

3. The attempt at a solution

tan[arctan(8x-8)]=tan(-1)
8x-8=tan(-1)
x=(1/8)(tan(-1)+8)
x=(1/8)(-(tan(1)+8)
x=

I am stuck on the last part since the homework says Simplify the above equation. (Round your answers to three decimal places.) and when I put in -2.186 its wrong.
 

Curious3141

Homework Helper
2,830
85
1. The problem statement, all variables and given/known data

arctan(8x-8)=-1

2. Relevant equations

I'm sure what this part wants.

3. The attempt at a solution

tan[arctan(8x-8)]=tan(-1)
8x-8=tan(-1)
x=(1/8)(tan(-1)+8)
x=(1/8)(-(tan(1)+8)
x=

I am stuck on the last part since the homework says Simplify the above equation. (Round your answers to three decimal places.) and when I put in -2.186 its wrong.
Your working is right. I initially thought you were putting the calculator in degrees, but that's not it. You must be doing something else wrong to get that wrong value.

Anyway, put your calculator into radians (RAD) mode and work that out again. Pay attention to where all the brackets are, better still work out what 8 - tan(1) is first, then divide by 8.
 

Dick

Science Advisor
Homework Helper
26,252
615
I do not get (1/8)(-tan(1)+8) to be equal to -2.186. How did you get that? What's tan(1)?
 
sorry I just realized that it was for a different problem my answer for this was .805
 

Curious3141

Homework Helper
2,830
85
sorry I just realized that it was for a different problem my answer for this was .805
Right answer.
 

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