For this round we were working on SAT prep. So basically, we continued focus on SAT but this time in class we wrote down what we haven’t learn and within this year our teacher will teach us a few of those topic. This round we learn about imaginary number, complex number, functions and quadratic. For function and quadratic we learn and practice in Khan Academy algebra 1.
Imaginary number ⇒ i
i = √-1
i^2= -1
i^3= -i
i^4= 1
Complex number ⇒ a +bi
a = real number
bi = real number times by imaginary number
Example: 5+2i
* imaginary function
a/bi⇒ a/bi*bi/bi⇒ ai/bi²⇒ -ai/b
Example: 5/3i ⇒ 5/3i * 3i/3i ⇒ = – 15i/9
*multiplying by the conjugation “a doesn’t have to be the same”
a/(b + i )⇒ (a/(b + i)) × ((b – i) ÷ (b – i)) ⇒ (a – bi) ÷ (a – bi²) ⇒ (± a – bi) ÷ (b)
Example:
4 ÷ (9 + i) ⇒ (4 ÷ (9 + i)) × ((9 – i) ÷ (9 – i)) ⇒ ((36 – 7i) ÷ (81 – i²)) ⇒ ((36 – 7i) / 82)
