If f is a real- valued differentiable fu...

If f is a real- valued differentiable function such that `f(x)f'(x) lt 0` for all real x, then

f(x) must be an increasesing function

f(x) must be an decreasing function

`|f(x)|` must be an increasing function

`|f(x)|` must be an decreasing function

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WB JEE PREVIOUS YEAR PAPER-QUESTION PAPER 2012-MULTIPLE CHOICE QUESTIONS

Let P (2,-3), Q(-2, 1) be the vertices of the triangle PQR. If the cen...
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lim(x to 0) (pi^(x)-1)/(sqrt(1+x)-1)
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If f is a real- valued differentiable function such that f(x)f'(x) lt ...
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Rolle's theorem is applicable in the interval [-2,] for the function
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The solution of 25(d^(2)y)/(dx^(2))-10(dy)/(dx)+y=0, y(0)=1, y(1)=2e^(...
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Let P be the midpoint of a chord joining the vertex of the parabola y^...
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The line x=2y intersects the ellipse (x^(2))/(4)+y^(2)=1 at the points...
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The eccentric angle in the first quadrant of a point on the ellipse (x...
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The transverse axis of hyperbola is along the x-axis and its length is...
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A point moves in such a way that the difference of its distance from t...
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The number of integer values of m, for which the x-coordinates of the ...
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If a straight line passes through the point (alpha, beta) and the port...
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The coefficient of x^(10) in the expansion of 1+(1+x)+...+(1+x)^(20) i...
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Examine the consistency of the system of equations x+ y +z=1 2x+...
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Let A and B be two events with P(A^(C))=-0.3, P(B)=0.4 and )P(A nn B^(...
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Let p,q,r be the altitudes of a triangle with area S and perimeter 2t....
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Let C(1) and C(2) denote the centres of the circles x^(2)+y^(2)=4 and ...
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A straight line through the point of intersection of the lines x+2y+4=...
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Let P and Q be the points on the parabola y^(2)=4x so that the lines ...
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The incentre of an equilateral triangle is (1,1) and the equation of o...
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