Answer:
[tex]\cos Z = \dfrac{3}{5}[/tex].
Step-by-step explanation:
To express [tex]\cos Z[/tex] as a fraction in the simplest form, we can use the formula of cosine:
[tex] \Large\boxed{\boxed{ \sf \cos (Angle) = \dfrac{\textsf{adjacent}}{\textsf{hypotenuse}}}}[/tex]
In this case:
- Adjacent= YZ
- Hypotenuse= XZ
Substitute the value, we get
[tex]\begin{aligned} \cos \, Z &= \sf \dfrac{YZ}{XZ} \\\\ &= \dfrac{21}{35} \\\\ &= \dfrac{3 \cdot \cancel{7}}{ 5 \cdot \cancel{7}} \\\\ & =\dfrac{3}{7} \end{aligned} [/tex]
Therefore, [tex]\cos Z[/tex] expressed as a fraction in simplest form is:
[tex] \Large\boxed{\boxed{\cos Z = \dfrac{3}{5}}}[/tex]
