What is derivative
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A question here .
A function is defined by y= 2x^2/x-1 where x>2.
a).find e` expression for dy/dx.
b).show y=2x^2/x-1 is an increasing function. -
a) using quotient rule,Originally posted by dbowie:A question here .
A function is defined by y= 2x²/(x-1) where x>2.
a) find the expression for dy/dx.
b) show y=2x²/(x-1) is an increasing function.
dy/dx = [4x(x-1)-2x²(1)]/(x-1)² = 2x(x-2)/(x-1)²
b) for x>2, (x-2)>0, and thus dy/dx>0.
since dy/dx is always +ve for x>2, y is an increasing function for x>2. -
ok .. my wings are not stiff enough to fly .. but thanks all for letting me know some subtle knowledge about this topic
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Since u want to noe the surface,
in simple english team....
dx means small change of x
dy means small change of y
dx/dy means small change of x / small change of y
y so ma fan leh ???
Coz, every simple fomula, they need to be a prove for it...
Mathematics is the proof for most science...
And there is no term tat describe ever increasing x ... So, they name it as "dx"... Then, can describe everything in the world using mathematics liao... -
no more called AO it's now called H1Originally posted by ^tamago^:This topic is only taught from Secondary 3 onwards (in Additional Mathematics) or 'AO' Mathematics in JC (for those who did not take Add. Maths in Sec Sch). -
okiesOriginally posted by unclebutcher:no more called AO it's now called H1