Question

find the values of x for which x^4+2x is an increasing function

Answer 1

Answer:

don't know ok na ki baat nhi

Answer 2

Step-by-step explanation:

f(X)=X4−2X2

f′(x)=4x63−4x(∵f(x)=0)

⇒4x3−4x=0

⇒4x(x2−1)=0

⇒4x=0 or x2−1=0

⇒x=0 or x=±1

Here, point x=0,1,−1 divides real number line into four interval (−∞,−1),(−1,0),(0,1) and (1,∞)

(a) For interval (−∞,−1)

f′(x)=4x3−4x

At x=−2,f′(x)=4x(−2)3−4(−2)

=−32+8=−24<0

Like this it can be shown for other points (f′(x)<0).

(b) For interval (−1,0)

F′(x)=4x3−4x

For x=−0.5

 f′(x)=4×(−0.5)3−4×(−0.5)

=