Let $x, y, z$ be positive numbers such that $x+y+z=26 \text { and } y=3 x$ If $x^2+y^2+z^2$ is to be least, then the value of $x$ is

JEE MATHEMATICS MCQ: MAXIMA & MINIMA

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Application +4 | -1

Let

x, y, z

be positive numbers such that

x+y+z=26 \text { and } y=3 x

x^2+y^2+z^2

is to be least, then the value of

x

View answer and explanation

Correct option: B

The correct answer is B (4) because the minimum value of

x^2 + y^2 + z^2

occurs when

x = 4

, which is found by minimizing the function using calculus.

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f(x)=\left(1+b^2\right) x^2+2 b x+1

m(b)

f(x)

b

m(b)

f: R \rightarrow R

f(x)=(x-3)^{n_1}(x-5)^{n_2}, n_1, n_2 \in N

|2 a x-3|+|a x+1|+|5-a x|=\frac{1}{2}

f(x)=2 x^{3}+(2 p-7) x^{2}+3(2 p-9) x

x<0

x>0

p

f\left( x \right)

f\left( x \right) = {\tan ^{ - 1}}x - \frac{1}{2}{\log _e}x

\left[ {1/\sqrt 3 ,\;\sqrt 3 } \right]

f(x)=\left(\frac{\sqrt{3 e}}{2 \sin x}\right)^{\sin ^{2} x}, x \in\left(0, \frac{\pi}{2}\right),

\frac{k}{e}

\left(\frac{k}{e}\right)^{8}+\frac{k^{8}}{e^{5}}+k^{8}