一个大圆里面切了一个小圆,说小圆的outside diameter is equal to inside radius of the large circular. And the cross-section area of the large circular is 49pai, what is the cross-section area of the small circular?
p(x)=ax^2+bx+c, this line are -1 and -3 at zeroes, p(5) is positive?
i. y intercept is 3
ii. P(-4)-P(-3) is negative
a(-1)^2+(-1)b+c= 0 a(-3)^2+(-3)b+c=0
so 8a=2b so b=4a so ax^2+4ax+c=0=p(x)
i. c=3, so ax^2+4ax+3 x=5 get 25a+20a+3=45a+3 45a+3 could be >0 or less than <0 so 1 is not right
ii. x=-4, get p(x)=ax^2+bx+c= 16a-16a+c=c x=-3, get 9a-12a+c= c-3a c-(c-3a)<0, so 3a<0, so a<0 the max point is x=-b/2a= -4a/(2a)=-2 and for x>-1, the curve will move downward, so for x=5, the function is <0