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Solve 8(4^x ) – 9(2^x ) + 1 = 0

At first this equation seems tricky, but we can perform a clever substitution to simplify it. We notice that if let y = 2^x, then we can rewrite this as: 8(y^2) - 9y + 1 = 0 This now becomes a simple quadrat...
DS
Answered by Daljit S. • Maths tutor
9896 Views

Factorise fully 8y + 4y^2

This question relies on knowledge of algebraic expressions and highest common factors. What is the highest common factor which goes into the expressions 8y and 4y^2. The answer is 4y. This is then taken on t...
AT
Answered by Abhinav T. • Maths tutor
8554 Views

What are the different forms of complex numbers and how do you convert between them?

Complex numbers have three primary forms: the general form, z=a+ib; the polar form, z=r(cosθ+isinθ); and the exponential form, z=rexp(iθ). To convert from the general form to either form you need to find r a...
PL
41843 Views

Find the stationary points on the curve y = x^3 + 3x^2 - 9x - 4

A stationary point is where the gradient is exactly zero - the curve is neither increasing or decreasing. This means that we need to differentiate y to find dy/dx and then set this equal to 0. Doing this, us...
RR
Answered by Richard R. • Maths tutor
17352 Views

Calculate the standard enthalpy of combustion of a methane sample by using the standard enthalpies of formation.

Write the equation and balance it. CH4 + 2O2 --> CO2 + 2H2O Assign the enthalpies of formation and the sign of the energy value with the corresponding molecule (Will demonstrate my technique if needed). e...
AC
Answered by Axel C. • Chemistry tutor
29514 Views