Melody

Use the quadratic formula

Thanks Heureka :)

I have only just started working through this.

I am sure it is very clear and I will have no problem following it.

However, I would not have been able to put that string of logic together myself.  

Maybe as I work through it some light may come on for me,

I hope so  :))

A pair of jeans is 90 cm long. At first wash shrinkage of 4%. How many cm shrink then?

4% of 90

4/100*90 = 3.6 cm

**

\(\frac{2.5\times 10^{12}}{5\times10^6}\\ =0.5\times 10^6\\ =5\times 10^{-1}\times 10^6\\ =5\times 10^{5}\\\)

Almost Pills but not quite.

Scientific notation must start with a number between 1 ( (included) and 10 (not included)

Use the calc on the home page !

the value of a $3,000 investment at 5% annual interest is found to be A(t)=3000(1.05)^t at t years after the initial investment. find the value after 6 years.

Just replece the t with a 6 and put it into the calculator

A(t)=3000(1.05)^t

A(6)=3000(1.05)^6

3000*(1.05)^6   ??? 

sin(x) - sin(x) * cos^2(x)

\(sin(x) - sin(x) * cos^2(x)\\ =sin(x) (1- cos^2(x))\\ =sin(x) sin^2(x)\\ =sin^3(x)\\ \)

sin^4(x) - cos^4(x) divided by sin^2(x) - cos^2(x)

\(\frac{sin^4(x) - cos^4(x) }{sin^2(x) - cos^2(x)}\\ =\frac{(sin^2(x) - cos^2(x))(sin^2(x) + cos^2(x)) }{sin^2(x) - cos^2(x)}\\ =\frac{sin^2(x) - cos^2(x)}{sin^2(x) - cos^2(x)}\\~\\ =1 \qquad where \;\;\; x\ne \frac{\pi+2n\pi}{4} \;\;\;n\in Z\)

That is great :)