9514 1404 393
Answer:
Step-by-step explanation:
The conjugate is found by changing the sign of the square root term.‡ (For this purpose, i = √-1.)
a) the sign of 3i is changed: 2 + 3i
b) the sign of sqrt(-5) is changed: 8 -sqrt(-5) = 8 -i√5
c) the sign of 2i is changed: 7 +2i
d) the sign of sqrt(7) is changed: 4 +√7
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‡ Actually, the conjugate of a binomial is formed by changing the sign <em>between</em> terms. The purpose is to allow the product of the binomial and its conjugate to be the difference of squares.
Conventionally, the conjugate of a complex number is the value with the sign of the imaginary part reversed. That is why (-2i+7)* = 7+2i.
Answer: 0.27£
Explanation:
9 apples + 9 bananas = 2.43
9(apple + banana) = 2.43
Apple + banana = 2.43/9
Apple + banana = 0.27£
Therefore, the cost of an apple AND a banana is 0.27£
Answer:
Step-by-step explanation:
The directrix of the parabola is the horizontal line with the eqaution 
The focus of the parabola is at point (-4,10), than the axis of symmetry of the parabola is the perpendicular line to the directrix passing through the focus. Its equation is 
The distance between the directrix and the focus is 
so 
and the vertex is at point 
Parabola goes in positive y-direction, hence its equation is
where 
is the vertex, so the equation of this parabola is
