Question
Question: Find \(\tan {53^ \circ }38'\) A. 1.23 B. 0.45 C. 0.56 D. 1.35...
Find tan53∘38′
A. 1.23
B. 0.45
C. 0.56
D. 1.35
Solution
Hint : We know that the degree is a measure of an angle, it is also known as arc degree because a plane angle is a measurement of full rotation of 360°. Since degree is a frequently used unit to measure an angle one may confuse it to be an S.I unit but the S.I unit for angle measurement is radian.
Complete step-by-step answer :
Since one full rotation makes an angle 2π. So one degree is 3602π=180π radians. A degree is further subdivided in minutes and seconds. This notation is DMS notation represented by degree-minutes –seconds. One degree is divided into
⇒1∘=60′ minutes in an arc
⇒1′=60′′ (one minute is equal to 60 seconds)
Now let us convert the above angle into a complete degree for this we will have to convert 38’ into degrees and add it to 53°,
⇒60′=1∘ ⇒1′=(601)∘ ⇒38′=(6038)∘=0.63∘
Therefore, now the angle gets converted and the final value to be found out is
⇒tan53∘38′=tan53.63∘
We know that tangent of A can be written as
⇒tanA=cosAsinA
Similarly
⇒tan53∘38′=tan53.63∘ ⇒tan53.63∘=cos53.63∘sin53.63∘=1.35
We can now calculate the value for this angle using a calculator or from a trigonometric value table, because we don’t have formula or trigonometric properties to calculate the value for this angle like we do for other trigonometric angles like 45°, 15°etc. therefore we have to remember this value as it is.
Note : All the trigonometric functions have got a very important property in common that is periodicity. Remember that the trigonometric ratios are real numbers as long as angle A is real. Trigonometric functions are also called circular functions.