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Where does the value of $b^2 - 4ac$ come from for the discriminant?? The value under the square root sign in the quadratic formula. Why is the discriminant useful?? It tells you how many real roots a quadratic has. What is the formula for the discriminant?? $$ b^2 - 4ac $$ Why must a positive discriminant mean two real roots?? The square root of a positive number has two possible solutions. Why must a zero discriminant mean one repeated root?

See [[Further Maths - Solving Systems of Equations Using Triangle Method]]S [[Further Maths - Solving Systems of Equations Using Matricies]]S Backlinks [[Maths - Syllabus]]S Metadata date: 2020-10-24 13:06 tags: - '@?maths' - '@?public' title: Maths - Simultaneous Equations

Is a stack FIFO or LIFO?? LIFO. Where do you remove items from the stack?? From the top. What does LIFO stand for?? Last-in First-out What does the Pop operation do to a stack?? Returns and removes the item at the top of the stack. What does the Top operation do to a stack?? Returns but doesn’t remove the top item of the stack. What does the Push operation do to a stack?? Puts a new item of the top of a stack.

How would a mean height change if everyone stood on chairs?? It would increase by the height of the chairs. How would a standard deviation for height change if everyone stood on chairs?? It would not change. How would a mean height change if everyone was 3 times taller?? It would be 3 times bigger. How would a standard deviation for height change if everyone was 3 times taller?? It would be 3 times bigger.

What does $\mathbb{Z}$ represent?? The set of integers. What does $\mathbb{Q}$ represent?? The set of rational numbers. What does $\mathbb{N}$ represent?? The natural numbers. What does $\mathbb{R}$ represent?? The real numbers. What is an ordinal number?? A number describing a position of something. Backlinks [[Computing - Syllabus]]S Metadata date: 2020-10-22 11:12 tags: - '@?computing' - '@?public' title: Computing - Number Systems

What is special about the horizontal and vertical components of a projectile?? They can be treated seperately. If you have two bullets, one which is fired from a completely level gun and one that is dropped at the exact same height and time as the other bullet being fired, which lands first?? They both land at the same time. Why do two bullets, one fired from a gun and one stationary, hit the ground at the same time?

Summary In summary, what is the roots of polynomials topic about?? Exploring the underlying relationship between the roots of a polynomial and the coefficient of each term. Basic Notations What are the two roots of a quadratic called?? $$ \alpha, \beta $$ What are the three roots of a cubic called?? $$ \alpha, \beta, \gamma $$ What are the four roots of a quartic called?? $$ \alpha, \beta, \gamma, \delta $$ Definitions What is the sum of the roots $\alpha + \beta$ equal to for a quadratic?

What are the two conditions for equilibrium?? Net force is zero Net moment is zero What is the name for two forces in an arrangement like the following?? PHOTO Is the following a couple PHOTO?? Yes. Is the following an equilibrium PHOTO?? No. Describe the motion as a result of PHOTO?? The object will spin with increasing angular velocity. When do couples produce a turning effect?? When there is a perpindicular distance between them.

What is a summary of encryption?? A way of making sure data cannot be understood if you don’t possess the means to decrypt it. What is a Ceasar cipher?? A method of encryption where you shift the letters along by a consistent amount. What is a brute-force attack?? Where you attempt every possible key to decrypt ciphertext until one works. What is another name for a one-time pad?? A Vernam cipher What is another name for a Vernam cipher?

Why is compression needed?? Because data is constantly being moved around computer systems and networks so a smaller amount of data can be beneficial. What are the two types of comression?? Lossy Lossless What’s an example of a lossy image compression format?? JPG What’s an example of a lossy music compression format?? MP3 What is the definition of run length encoding?? A basic method of compression that summarises consecutive patterns of the same default.

What does MIDI stand for?? Musical Instrument Digital Interface What is the difference between a live recording and MIDI?? Midi is recording a synthesised sound. What is the advantage of MIDI?? Full sound signal doesn’t need to be transmitted, only instructions to play the sound. If vector graphics are the instructions to draw an image, MIDI is?? The instructions to make a sound. Backlinks [[Computing - Syllabus]]S Metadata date: 2020-10-15 11:30 tags: - '@?

What is the main difference between an analogue and digital signal?? Analogue signals are continuous while digital signals are discrete. In one sentence, how does a digital-to-analogue converter for sound work?? Sound is captured by a microphone which is sampled at regular intervals and these samples are converted to binary. The frequency at which samples of a sound are taken is called?? The sampling rate. When an analogue sound signal is being converted to digital, what value is sampled?