the set of values of a for which the roots of equation (a-3)x²-2ax+5a=0 are positive is?? ans is(3,15/4]. how plz plz plz explain
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for +ve roots and for real n disti ct root discrimnant must be greater than 0 . u you put alue in equation from given option in place of A and check value of d
POSITIVE:
yes for sure this is a gud objective approach (thumps up)
but subjectively, i tried 1. D>=0 2. f(0)>0 3.-b/4a>0...... and took the intersection of three.......but ended with [15/4 to infinity)
so sir ...could u plz xplain me whats wrong in this plz ??
> means greater up there
i will solve this question but you know its impossible to write equation by mobile text
wait on i will send a short trick earlier
that would b great help!!! ty
the short is not applicable on this question but another question just like ax2+by+c lies in interval of (....) like this and find the value of c lies in the interval . in this case you diffrentiate the quadratic and find the value of x and find is value lies on the interval.. such type of question asked in jee 2013
okay!!
thks again
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