Algebra 2 questions

q1) Find the real value of the parameter ' t ' for which there is at least one complex number z = x +iy satisfying the condition | z + 3 | = t2 - 2t + 6 and the inequality |z - 3√3 i| < t2

q2)
solve x3 - 3 - { x } = 0 where { . } denotes fractional part .

sorry to tell but i don't have answer to this so plese post ur solution .

4 Answers

62
Lokesh Verma ·

second one is not very difficult..

draw the graph... you have to find the point where x^3-3={x}

so x^3-3 should lie between 0 and 1

so x^3 should lie between 3 and 4

so x should lie betweeen 1 and 2

so {x} = x-1

so the given equation can be rewritten as

x3-3- (x-1) = x3 -x -2 = 0

This will have to be solved by the cos 3 theta trick or the solution to a cubic equation...

1
Manmay kumar Mohanty ·

and wat abt the first one bhaiya [7]

62
Lokesh Verma ·

The first one seems a geometry problem

Find the real value of the parameter ' t ' for which there is at least one complex number z = x +iy satisfying the condition | z + 3 | = t2 - 2t + 6 and the inequality |z - 3√3 i| < t2

What you can see is find the relation between a and b such that

there is at least one complex number z = x +iy satisfying the condition | z + 3 | = a and the inequality |z - 3√3 i| < b

What will you do??

The distance from the point -3 and 3√3i is 6

so √a+√b should be _____ than 6?

now can you try?

1
Manmay kumar Mohanty ·

yes sir i will try further.
thnks for the explanation u suggested and gave it in the thread.
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