\(ABC\) is a triangle right angled at \(B\). If \(AC = 8\) units, then what is the area of the triangle of maximum area?
16 square units
With the right angle at \(B\), let \(AB=x\) and \(BC=y\), so \(x^2+y^2=AC^2=64\). The area is \(\dfrac{1}{2}xy\), which by AM-GM is maximum when \(x=y\), giving \(x^2+y^2=2x^2=64\), so \(x^2=32\) and \(xy=32\). Hence the maximum area is \(\dfrac{1}{2}(32) = 16\) square units.
What is the slope of the tangent of y = cos -1 (cos x) at x = \(-\frac{\pi}{5}\) ?
The maximum value of \(\sin \left( {{\rm{x}} + \frac{{\rm{\pi }}}{6}} \right) + \cos \left( {{\rm{x}} + \frac{{\rm{\pi }}}{6}} \right)\) in the interval \(\left( {0,\frac{{\rm{\pi }}}{2}} \right)\) is attained at
What is the minimum value of [x(x – 1) + 1] 1/3 , where 0 ≤ x ≤ 1?
What is the least value of m(θ) ?
Let P be the median, Q be the mean and R be the mode of observations x1, x2, x3, .....xn. Let \(S=\sum_{i=1}^n\left(2 x_i-a\right)^2\) S takes minimum value, when a is equal to
What is the maximum value of xy ?
Consider the following statements in respect of the function f(x) = sin x:
1. f(x) increases in the interval (0, π).
2. f(x) decreases in the interval \(\left(\dfrac{5\pi}{2},3\pi\right).\)
Which of the above statements is/are correct?
What is the maximum value of sin 2x ⋅ cos 2x?
How many extreme values does sin4x + 2x, where \(0 < x < \frac{\pi}{2} \) have ?
In which one of the following intervals is the function \(f(x) = \frac{x^3}{3}-\frac{7x^2}{2} + 6x + 5\) decreasing?
What is the slope of the tangent of y = cos -1 (cos x) at x = \(-\frac{\pi}{5}\) ?
The maximum value of \(\sin \left( {{\rm{x}} + \frac{{\rm{\pi }}}{6}} \right) + \cos \left( {{\rm{x}} + \frac{{\rm{\pi }}}{6}} \right)\) in the interval \(\left( {0,\frac{{\rm{\pi }}}{2}} \right)\) is attained at
The derivative of the function y = 3|x| + 1 at the point x = 0 is
Given that f(x) = x 1/x , x > 0 has the maximum value at x = e, then
What is the minimum value of [x(x – 1) + 1] 1/3 , where 0 ≤ x ≤ 1?