find values of x,for which the function f(x)=x^3+12x^2+36x+6 is increasing
first find the derivative the required values are when the derivative is greater than zero
3x^2+24x+36 = y1
@ikram002p
right now equate this to zero and solve for x to find the turning points on the graph and then we can find values for x the required values of x 3(x^2 + 8x + 12) = 0
the function will factor
can you factor it?
i did not understand
@cwrw238
to factor it you need 2 numbers whose product is 12 and when added they give 8 if we call them a and b we then get (x + a)(x + b) = 0
3(x+2)(x+6)
right so 3(x + 2)(x + 6) = 0 so x+2 = 0 and x +6 = 0 and x = -2 or -6
after that
these are the values of x for which the graph of the function has a turning point - now we need to find the nature of these points - maximum, minimum or point of inflection
to do this we can find second derivative this is derivative of 3x^2 + 24x + 36 can you do that?
6x+24
this is y2 ,right?
i have to go @rational @praxer might help
thank u green mam @ikram002p
algorithm. 1. Differentiate the function. 2. equate it to zero 3. those regions where the derivative it > 0 is the region where the function is increasing. 4. You can do so, by the wavy curve method.
yes now the sin of this second derivative tells you if the points are maximum of minimum x = -2: y2 = 6(-2) + 24 = 12 which id positive - so minimum x = -6 y2 = 6(-6) + 24 = -12 - maximum
if it is +ve then mimimum? @cwrw238
so when x < -6 the function is increasing and also its increasing when x > -2
yes
how @cwrw238
$$ f(x)= x^3+12x^2+36x+6$$ $$f'(x)=3x^2+24x+36$$ $$f'(x)=(x+6)(x+2)=0$$ The 2 and 6 is the points where the slope is 0 or the function is parallel to the x axis. now Use the wavy curve method to find the region where the function is > 0 .
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