JEE mathematics

Find the period of the function f(x) = sin ((π x)/(2) ) + cos ((π x)/(3) ) — JEE Mathematics

JJulienMoreau51 Asked 2mo ago 1,054 views 1 answer

Find the period of the function $f(x) = \sin\left(\frac{\pi x}{2}\right) + \cos\left(\frac{\pi x}{3}\right)$.

1 Answer

VAVidaara Admin ✓ Vidaara Team ✓ Accepted · 2mo ago ▲ 25
  • The period of $\sin(kx)$ is $\frac{2\pi}{|k|}$. Here, $k_1 = \frac{\pi}{2}$, so the period $T_1 = \frac{2\pi}{\pi/2} = 4$.
  • The period of $\cos(kx)$ is $\frac{2\pi}{|k|}$. Here, $k_2 = \frac{\pi}{3}$, so the period $T_2 = \frac{2\pi}{\pi/3} = 6$.

The period of the combined function $f(x)$ is the Least Common Multiple (LCM) of $T_1$ and $T_2$:

$$T = LCM(4, 6) = 12$$

Answer: 12

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Discussion (4)

SD
Brilliant explanation, the substitution step is what I kept missing.
Siddharth Das · 2mo ago
T
Brilliant explanation, the substitution step is what I kept missing.
TharushiFernando19 · 2mo ago
A
Is there a faster shortcut for this in the actual exam? Time is tight.
AayushaRai25 · 2mo ago
SP
Saved me before my mock test. Much clearer than my coaching notes.
Suresh Pillai · 2mo ago
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