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You are not logged in. #1 20130622 23:04:52
quadratic equationswell i have 3 questions here which are prove based friendship is tan 90°. #2 20130623 02:11:55
Re: quadratic equationshi niharika_kumar This comes straight from the quadratic formula. If the square root part exists and is not zero then D>0 means two real roots If it is zero then D=0 means just one real root And if there is no real square root D<0 means no real roots. Q2. Find out D and consider what is needed for real roots. You should find D can never be > 0 and is equal to 0 for that condition. Q3. (p + r)^2 ≥ 0 but pr = 2(q+s) So consider what happens if p^2 < 4q AND r^2 < 4s .... add these two equations, make use of the above and you should arrive at something that can never be true. Therefore one or other equation has real roots. Working on Q1 Several hours later: Q1 has me beat at the moment. Here's my analysis; maybe someone can spot an error. For equal roots So I plotted the graph for a variety of values of a and c trying to find some xaxis crossing points to get a 'b' for my chosen 'a' and 'c' I couldn't get the graph to cross the xaxis for any a and c values ??? So I thought I'd apply the D = rule to this quadratic. This will always be negative unless a = c In that one case The original certainly has equal roots in this case and the required result also follows. As far as I can tell there are no other real solutions. Help Bob You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei #3 20130623 06:23:45
Re: quadratic equationsThought I'd start a fresh post rather than adding to the above. Then it must also be possible to prove Subtracting (ii) from (i) and by the symmetry that must work for c too, so a = b = c. So <equal roots> => a = b = c AND <expression to prove> => a = b = c Only trouble is, this still gets me no nearer to <equal roots> => <expression to prove> Bob You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei #4 20130623 18:00:26
Re: quadratic equationsthnx for the solution ! friendship is tan 90°. #5 20130623 18:07:54
Re: quadratic equationshi niharika_kumar You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei 