Maths 7

Basics Positive and Negative Angles

Angle generated by a counter-clockwise rotation, we call angle a Positive Angle. On the other hand, if an angle is generated by a clockwise rotation we call angle a Negative Angle

July 20, 200967222 https://chemistrylearning.com/positive-and-negative-angles/
How to Graph Quadratic Functions?

A quadratic function is of form y = ax² + bx + c where a ≠ 0 and a, b, c are real number. Graph of quadratic functions are always a parabola either opening upwards or downwards.
To plot graph of any quadratic function, we need answers of these question
What is sign of ‘a’ or coefficient of x2 in quadratic function?
Whether the graph of quadratic function intersects with x-axis? And if it does at what point does it intersect?

March 28, 200919419 https://chemistrylearning.com/graphing-quadratic-functions/
How to find roots of any complex number?

Let z = (a + i b) be any complex number. The nth root of complex number z is given by z1/n where n → θ (i.e. set of rational numbers).
Convert the given complex number, into polar form.
Add 2kπ to the argument of the complex number converted into polar form.
Raise index 1/n to the power of z to calculate the nth root of complex number.

March 27, 200921389 https://chemistrylearning.com/how-to-find-roots-of-any-complex-number/
How to convert complex number in geometrical form to polar form?

The complex number z in geometrical form is written as z = x + iy.In geometrical representation complex number z is represented by a point P(x, y) on the complex plane or the argand plane where OA =x is x-intecept and AP=y is y-intercept.

In polar representation a complex number z is represented by two parameters ‘r’ and ‘θ’. Parameter ‘r’ is the modulus of complex number and parameter ‘θ’ is the angle which the line OP makes with the positive direction of x-axis. It is also called argument of complex number and is denoted by arg(z).Finding the value of these two parameters from parameters x and y will help us convert the complex number to polar form.

March 1, 200970265 https://chemistrylearning.com/geometrical-to-polar-conversion/
How to find the logarithm of a complex number?

Let a + i b be a complex number whose logarithm is to be found.
Step 1: Convert the given complex number, into polar form.
Where amplitude and argument is given.
Step 2: Use Euler’s Theorem to rewrite complex number in polar form to exponential form.
There r (cos θ + isinθ) is written as reiθ. This means that
a+ i b= reiθ
Step 3: Take logarithm of both sides we get.

March 1, 200947284 https://chemistrylearning.com/logarithm-of-complex-number/
How to find modulus of complex number?

Argand Plane is used to represent the complex number. The horizontal axis of Argand plane represents the real part while vertical axis represents the imaginary part of complex number.
The modulus of complex number is distance of a point P (which represents complex number in Argand Plane) from the origin....

March 1, 200915433 https://chemistrylearning.com/modulus-of-complex-number/
How to find the reciprocal of a complex number?

Step 1 : Invert the number
If z = a + i b is a complex number, then reciprocal of it is given by..
Step 2: Multiply numerator and denominator by conjugate

Multiply numerator and denominator of the inverted number by conjugate of denominator...
Step 3: Simplify and find the reciprocal

Simplify above equation in step (2). Numerator is multiplied by 1 and is already simplified...

March 1, 200969570 https://chemistrylearning.com/reciprocal-of-a-complex-number/