Step 1: Read the question and known about the complementary angles

LINK: https://byjus.com/maths/trigonometric-ratios-of-complementary-angles/

GIVEN: \sin 75\degree + \tan 65\degree

Step 2: Reduce the angles of the trigonometric ratios by using the complementary angles.

We can write \sin 75\degree = \cos (90\degree - 75\degree )

= \cos 15\degree

\cos 65\degree = \sin (90\degree - 65\degree )

= \sin 25\degree

Step 3: Plugging the calculated values in the given equation

EXAMPLE: \sin 75\degree + \cos 65\degree

\cos 15\degree + \sin 25\degree (since step 2)

Hence, trigonometric ratios of angles between 0\degree \text{ and } 45\degree