Math Problem Statement

solve sinx -1 = cosx

Solution

We are given the equation:

sin(x)1=cos(x)\sin(x) - 1 = \cos(x)

Step 1: Rearrange the equation

First, isolate one trigonometric function on one side of the equation:

sin(x)=cos(x)+1\sin(x) = \cos(x) + 1

Step 2: Use the Pythagorean identity

We know the Pythagorean identity:

sin2(x)+cos2(x)=1\sin^2(x) + \cos^2(x) = 1

Now, square both sides of the equation sin(x)=cos(x)+1\sin(x) = \cos(x) + 1:

sin2(x)=(cos(x)+1)2\sin^2(x) = (\cos(x) + 1)^2

Step 3: Expand and simplify

Expand the right-hand side:

sin2(x)=cos2(x)+2cos(x)+1\sin^2(x) = \cos^2(x) + 2\cos(x) + 1

Now, substitute cos2(x)=1sin2(x)\cos^2(x) = 1 - \sin^2(x) into the equation:

sin2(x)=(1sin2(x))+2cos(x)+1\sin^2(x) = (1 - \sin^2(x)) + 2\cos(x) + 1

Simplifying:

sin2(x)=2sin2(x)+2cos(x)\sin^2(x) = 2 - \sin^2(x) + 2\cos(x)

Now, bring all terms involving sin(x)\sin(x) and cos(x)\cos(x) to one side:

2sin2(x)2cos(x)=22\sin^2(x) - 2\cos(x) = 2

Divide the whole equation by 2:

sin2(x)cos(x)=1\sin^2(x) - \cos(x) = 1

Step 4: Solve using a numerical or graphical method

This is a non-linear trigonometric equation, and solving it algebraically is quite complex. To find the exact solutions, we would typically use numerical methods or graphing.

Would you like me to help you solve this equation using a graphing or numerical method?

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Trigonometry
Algebra
Pythagorean Identity

Formulas

sin^2(x) + cos^2(x) = 1
sin(x) = cos(x) + 1

Theorems

Pythagorean Identity

Suitable Grade Level

Grades 10-12