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If `b^(2)ge4ac` for the equation `ax^(4)+bx^(2)+c=0` then all the roots of the equation will be real ifA. `bgt0,alt0,cgt0`B. `blt0,agt0,cgt0`C. `bgt0,agt0,cgt0`D. `bgt0,alt0,clt0` |
Answer» Correct Answer - B::D Put `x^(2)=y` Then the given equation can be writte as `f(y)=ay^(2)+by+c=0`……….i The givenn equation will have real roots i.e. Eq. (i) has two non-negative roots. Then `-b/age0` ltbr `af(0)ge0` and `b^(2)-4acge0`[given] `impliesb/ale0` `acge0` `impliesagt0,blt0,cgt0` `or alt0,bgt0,clt0` |
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