Question

How do you find the value of \[\cot 45^\circ \]?

Answer 1

Hint:
In the given question, we have been asked the exact value of a trigonometric ratio with a constant angle. By exact value, it means that if the value is in fractions, we have to convert it to decimals. This is achieved by dividing the numerator by the denominator. If the denominator is an irrational number, then we shift the irrational number to the numerator by rationalizing it.

Complete step by step answer:
We know, \[\cot \theta = \dfrac{{\cos \theta }}{{\sin \theta }}\]
So, we write the values of sine and cosine for those values and then divide them.
Now as we know, \[\cos 45^\circ = \dfrac{1}{{\sqrt 2 }}\]
And we also know that, \[\sin 45^\circ = \dfrac{1}{{\sqrt 2 }}\]
Hence we get, \[\cot 45^\circ = \dfrac{{\cos 45^\circ }}{{\sin 45^\circ }} = \dfrac{{\dfrac{1}{{\sqrt 2 }}}}{{\dfrac{1}{{\sqrt 2 }}}} = 1\]

Hence, the value of \[\cot 45^\circ \] is \[1\].

Note:
So, for solving questions of such type, we first write what has been given to us. Then we write down what we have to find. Then we write the formula which connects the two things. We have to take care if the denominator is irrational, if it is then we have to rationalize. When we are rationalizing the denominator as it is the only place where we could make an error.