and
By first writing , and then expanding brackets and using the fact that , show that
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and
By first writing , and then expanding brackets and using the fact that , show that
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Given that and :
Write down and
Show that and
Explain why
Use the results of parts (b) and (c) to work out , giving your answer in the form where and are real numbers.
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Given that and , find and where and are real numbers.
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By first working out , show that is a solution to .
Show that is another solution to .
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Using laws of surds and the fact that , find both solutions to the equation . Your answers should be given as multiples of .
Solve the equation for
In each case, give your answers in the form where and are real numbers. Confirm that the two methods give the same results.
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The two roots of a quadratic equation with real coefficients are and .
Given that , and that non-real roots to quadratic equations with real coefficients always occur in complex conjugate pairs,
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Given that ,
The other two roots of the cubic equation in part (a) (ii) are and , where is a non-real complex number and is a real number.
Given that non-real roots to cubic equations with real coefficients always occur in complex conjugate pairs,
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, where and are real numbers.
The roots of the equation are and .
Given that and , and that non-real roots to cubic equations with real coefficients always occur in complex conjugate pairs,
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Let , where and are real numbers, be a general complex number.
Show that .
For a complex number , a square root of is a complex number where and are real numbers and where
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Given that and , work out the following:
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Given that and :
Work out and
Hence or otherwise work out , giving your answer in the form where and are real numbers.
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For a general complex number , where and are real numbers, show that:
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Given that and find and where and are real numbers.
.
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Solve the following equations for , giving your answers in the form where and are real numbers:
In each case, be sure to show your working.
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Given that is one of the roots of a quadratic equation with real coefficients,
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Given that ,
Find the other two roots of the cubic equation in part (a) (ii), being sure to show clear algebraic working.
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, where and are real numbers.
Given that and are roots of the equation ,
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For a complex number , a square root of is a complex number where and are real numbers and where
Given that , show that and .
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Given that and , work out the following:
For part (iii) give your answer in the form , where and are real numbers.
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The complex number satisfies the equation .
Find , giving your answer in the form , where and are real numbers.
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Given that and , where and are real numbers, find the possible values of and .
Using your answers to part (a), write down values for and that will satisfy the equation
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The equation , where , has distinct non-real complex roots.
Find the range of possible values of .
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Given that is one of the roots of the quadratic equation , where and are real constants, find the values of and .
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Show that is a root of the cubic equation
Find the other two roots of the cubic equation in part (a), being sure to show clear algebraic working.
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, where and are real numbers.
Given that 3 and are roots of the equation , find the value of and the value of .
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For a complex number , a square root of is a complex number where and are real numbers and where
By expanding and solving the resultant equation for and , determine the two square roots of the complex number .
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For a general complex number , where and , show that
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Given that and , where and are real numbers, find the values of and .
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Find all the complex numbers for which .
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and are the three roots of the cubic equation
where .
Given that and that and are distinct non-real complex numbers, find the range of possible values of .
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Given that is one of the roots of the quadratic equation , where and are positive real constants, find the values of and .
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Work out the solutions to the equation . Be sure to show clear algebraic working.
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You are given that the complex number satisfies the cubic equation
where and are real constants.
By first calculating and , find the values of and .
Find the other two roots of the cubic equation.
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, where is a real constant.
Given that is a root of the equation , show that is a factor of .
Hence find the value of and solve completely the equation .
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The principal square root of a complex number is defined as
where and are real numbers and . If then the value for is chosen such that . Note that the other square root of will then be given by .
Show that
Given that , derive a formula for in terms of and , and explain why in this case will always have the same sign (positive, negative, or zero) as .
Hence show that in general
with the choice of the positive or negative value being dependent on the properties of .
Explain what must be true of for each of the following to be true:
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