Math Problem Statement

evaluate: 0.125 [8 cos(0^2) + 2(8 cos((0.25)^2)) + 2(8 cos(0.5^2)) + 2(8 cos(0.75^2)) + 8 cos(1^2)]

Solution

Let's evaluate the expression step by step:

We are given the following:

0.125[8cos(02)+2(8cos(0.252))+2(8cos(0.52))+2(8cos(0.752))+8cos(12)]0.125 \left[ 8 \cos(0^2) + 2 \left( 8 \cos(0.25^2) \right) + 2 \left( 8 \cos(0.5^2) \right) + 2 \left( 8 \cos(0.75^2) \right) + 8 \cos(1^2) \right]

Step 1: Evaluate the cosines.

  • cos(02)=cos(0)=1\cos(0^2) = \cos(0) = 1
  • cos(0.252)=cos(0.0625)\cos(0.25^2) = \cos(0.0625) ≈ 0.9980
  • cos(0.52)=cos(0.25)\cos(0.5^2) = \cos(0.25) ≈ 0.9689
  • cos(0.752)=cos(0.5625)\cos(0.75^2) = \cos(0.5625) ≈ 0.8469
  • cos(12)=cos(1)\cos(1^2) = \cos(1) ≈ 0.5403

Step 2: Plug in the values into the expression.

=0.125[8(1)+2(8(0.9980))+2(8(0.9689))+2(8(0.8469))+8(0.5403)]= 0.125 \left[ 8(1) + 2 \left( 8(0.9980) \right) + 2 \left( 8(0.9689) \right) + 2 \left( 8(0.8469) \right) + 8(0.5403) \right]

Step 3: Simplify inside the brackets.

=0.125[8+2(7.984)+2(7.7512)+2(6.7752)+4.3224]= 0.125 \left[ 8 + 2(7.984) + 2(7.7512) + 2(6.7752) + 4.3224 \right]

=0.125[8+15.968+15.5024+13.5504+4.3224]= 0.125 \left[ 8 + 15.968 + 15.5024 + 13.5504 + 4.3224 \right]

=0.125[57.3432]= 0.125 \left[ 57.3432 \right]

Step 4: Multiply by 0.125.

0.125×57.3432=7.16790.125 \times 57.3432 = 7.1679

Thus, the value of the expression is approximately 7.1679.

Would you like further details or have any questions?


Here are some related questions you could explore:

  1. How does the cosine function behave at different values of xx?
  2. What are other numerical methods for approximating integrals similar to this summation approach?
  3. How can you generalize this sum for other functions, not just cosine?
  4. What role does the coefficient 0.125 play in this evaluation?
  5. How would this expression change if sine was used instead of cosine?

Tip: Remember, cosine values oscillate between -1 and 1, making them useful for periodic function analysis.

Ask a new question for Free

By Image

Drop file here or Click Here to upload

Math Problem Analysis

Mathematical Concepts

Trigonometry
Cosine Function
Summation

Formulas

cos(x)
Summation of multiple terms

Theorems

Cosine properties
Basic trigonometric identities

Suitable Grade Level

Grades 10-12