Does anyone know this answer to this questions

ANSWER
-4.0
EXPLANATION
The given trigonometric equation is
[tex] \tan \: 45 \degree - 10 \: \cos \: 60 \degree[/tex]
From special angles or using the unit circle.
[tex]\tan \: 45 \degree = 1[/tex]
[tex] \cos \: 60 \degree = \frac{1}{2} [/tex]
We make the substitution to get:
[tex]1 - 10 ( \frac{1}{2} ))[/tex]
This simplifies to:
[tex]1 - 5 = - 4[/tex]
Hence the correct answer is -4.0