Question

F(t)= cos 5t (Laplace)

Answer 1

From the table of Laplace Transforms

$$L (\cos(at))=\dfrac{s}{s^2+a^2}$$

Then

$$L(F(t))=L (\cos(at))=\dfrac{s}{s^2+5^2}$$

$$L(F(t))=L (\cos(at))=\dfrac{s}{s^2+25}$$