Write i in trigonometric form. Since |i| = 1 and arg(i) = π/2, we have
i = exp(i π/2) = cos(π/2) + i sin(π/2)
By DeMoivre's theorem,
i² = exp(i π/2)² = exp(i π) = cos(π) + i sin(π)
and it follows that i² = -1 since cos(π) = -1 and sin(π) = 0.
6.9 x 10⁷ is a scientific notation.
6.9 x 10⁷ in standard form is 69,000,000
Scientific notation is used to represent very large numbers or very small numbers.
Scientific notation has three parts. Its parts are the coefficient, base of ten, and the exponents.
6.9 is the coefficient
10 is the base of 10
7 is the exponent
The must always be 1 digit before the decimal point in the scientific notation.
The exponent tells us the number of places the decimal point has moved. Its sign tells us the direction of the decimal point's movement.
Since the exponent is positive, it tells us that the decimal point moved from right to left.
69000000. to 6.9000000
If the exponent had a negative sign, it means that the decimal point moved from left to right.
example: 6.9 x 10⁻⁷
its standard form would have been .00000069
When you have a negative exponent, you move the base with the negative exponent to the other side of the fraction to make the exponent positive.
For example:
or 
or 
or 
Make the exponent positive
(this is as far as you can simplify)
Answer: a = 6
Step-by-step explanation:
The slope of the line is -1/2 so if y = -4, x = 6. In your case, x is a.
Hope this helps!
