Melody

(80p+19) /4   cm

100% +8% = 108% = 1.08

Use the change of base rule

$$\\x=log_8(23)\\\\
x=\frac{log23}{log8}$$

you can have it in whatever base you want - the answer will always be the same :)

With the web2 calc you don't even have to change the base

log(23,8)             $${{log}}_{{\mathtt{8}}}{\left({\mathtt{23}}\right)} = {\mathtt{1.507\: \!853\: \!985\: \!352\: \!337\: \!8}}$$

y=-5-5x^2 at (-2,-25)

Always remember that the fisrst derivative gives the gradient of the tangent to the curve!

y'=0-10x= -10x

x=-2    y'=+20

so the gradient is 20 and a point on the tangent is (-2,-25)

Now can you finish it?

$$3y^8*y^7 = 3*y^{8+7}=3y^{15}$$

I did a post on this recently

Here it is

Thansk Geno :)

$$\\10 log (0.003/10^{-12})\\
\\=10log(0.003*10^{12})\\\\
=10log(3*10^{-3}*10^{12})\\\
=10log(3*10^{9})\\\\
=10[log3+log10^9)\\\\
=10log3+90log10\\\\
=10log3+90\\\\
=90+10log3$$

Mmm   That is a bit vague Mellie :)))

Calculus is a strand of maths that is used to find instantaneous rates of change.

It can be used in many different ways.  It is very poswerful and a lot of fun once you get the hang of it.

Thanks Mellie, you are right, there is no distict 'end' point :)

$$\\z\frac{z}{1.2}+5\\\\
=z*\frac{z}{1.2}+5\\\\
=\frac{z}{1}*\frac{z}{1.2}+5\\\\
=\frac{z*z}{1*1.2}+5\\\\
=\frac{z^2}{1.2}+5\\\\
=\frac{10z^2}{12}+5\\\\
=\frac{5z^2}{6}+\frac{30}{6}\\\\
=\frac{5z^2+30}{6}\\\\$$