5/4 + 7/4 x cos(2x)+ 3/4 x cos(4x)- 1/8 x cos(2x) x cos(4x)
To evaluate the expression 5/4 + 7/4 x cos(2x) + 3/4 x cos(4x) - 1/8 x cos(2x) x cos(4x), we need to simplify it step by step.
Let's break it down:
1. Start with the term 5/4.
2. Next, we have the term 7/4 x cos(2x). To evaluate this, you'll need to know the value of cos(2x). If you have a specific value for x, you can substitute it into the expression to calculate cos(2x) using a scientific calculator.
3. Moving on, we have 3/4 x cos(4x). Similarly, you'll need to find the value of cos(4x) by substituting x into the expression and using a scientific calculator.
4. Lastly, we have -1/8 x cos(2x) x cos(4x). To evaluate this term, you'll need the values of both cos(2x) and cos(4x).
Once you have determined the values of cos(2x) and cos(4x), you can substitute them back into the expression and perform the necessary multiplications and additions to find the final result.