Find the Maximum and Minimum Value of 12 sin x − 5 cos x
Question:
Find the maximum and minimum values of the following trigonometrical expression: \[ 12\sin x – 5\cos x \]
Find the maximum and minimum values of the following trigonometrical expression: \[ 12\sin x – 5\cos x \]
Solution
We use the standard result:
\[ a\sin x + b\cos x \] has maximum value \[ \sqrt{a^2+b^2} \] and minimum value \[ -\sqrt{a^2+b^2} \]
Given expression:
\[ 12\sin x – 5\cos x \]
Here, \[ a=12,\qquad b=-5 \]
Now,
\[ \sqrt{a^2+b^2} = \sqrt{12^2+(-5)^2} \]
\[ = \sqrt{144+25} \]
\[ = \sqrt{169} \]
\[ =13 \]
Therefore,
Maximum value: \[ 13 \]
Minimum value: \[ -13 \]
Final Answer
\[ \boxed{\text{Maximum value }=13} \]
\[ \boxed{\text{Minimum value }=-13} \]