
It looks like there might be some confusion in your explanation. Let me clarify the steps for finding cos E in the given context.
Given that cos E = 10/26, and you want to find the length of EF in triangle ADEF using the trigonometric ratio sine (sin), you can follow these steps:
1. Start with the trigonometric identity:
![\[ \sin^2 E + \cos^2 E = 1 \]](https://img.qammunity.org/2024/formulas/mathematics/high-school/umxwmo9yxaycavquzjnzzq6aa59ba6es76.png)
2. Substitute the given value of cos E into the equation:
![\[ \sin^2 E + \left((10)/(26)\right)^2 = 1 \]](https://img.qammunity.org/2024/formulas/mathematics/high-school/351u56hnzjv2rgdusdykq3lpbb6q7prfjg.png)
3. Solve for
:
![\[ \sin^2 E + (100)/(676) = 1 \]](https://img.qammunity.org/2024/formulas/mathematics/high-school/jnoso8h7spgkntdglg4hlmggrj41l9fkoi.png)
![\[ \sin^2 E = 1 - (100)/(676) \]](https://img.qammunity.org/2024/formulas/mathematics/high-school/zptqj5ds797pmf78lqqa09cy2wyajvfjql.png)
![\[ \sin^2 E = (576)/(676) \]](https://img.qammunity.org/2024/formulas/mathematics/high-school/odvvhp433cc3zduk3f6kswkr7kktn3eig3.png)
4. Take the square root of both sides to find cos E:
![\[ \cos E = (√(576))/(√(676)) \]](https://img.qammunity.org/2024/formulas/mathematics/high-school/1qpg7dutrzqlqgx5d49dq5p461afmw6ih7.png)
![\[ \cos E = (24)/(26) \]](https://img.qammunity.org/2024/formulas/mathematics/high-school/8lzejgfb9g5bm8zniy5dk2aqkz3kt8fu27.png)
So,
, which is consistent with the information you provided. It seems there was an error in stating that sin D is given as 24/26, as sin D should be related to angle D, not E. If you have additional information or corrections, please provide them for further clarification.