A triangle has a base that is decreasing at onrate of Item/ s with the height being held constand. what is the rate of change of the area of the triangle if the height is 7cm? 5. use the first derivative test to find the location of all local extrema in the interval ( - 4 , 5 ) for the function . f ( x ) = ( 5 x - 4 ) elix . if there is more than one local maximamps minimum list them all if a local maximum or a local minimum does not occur on the - sterval , nots that in Your work