CameraIcon
CameraIcon
SearchIcon
MyQuestionIcon


Question

If the roots of the quadratic equation $$ x^{2}-4x-\log_{3}a=0 $$ are real, then the least value of $$a$$ is


A
81
loader
B
181
loader
C
164
loader
D
9
loader

Solution

The correct option is B $$ \dfrac{1}{81} $$
Given roots are real
$$\Rightarrow b^{2}-4ac\geq 0$$
$$\Rightarrow 16+4(\log_{3}a)\geq 0$$
$$log_{3}{a}\geq -4$$
$$a\geq 3^{-4}$$
Least value of $$a$$ is $$\dfrac{1}{3^{4}}=\dfrac{1}{81}$$ .

Mathematics

Suggest Corrections
thumbs-up
 
0


similar_icon
Similar questions
View More


similar_icon
People also searched for
View More



footer-image