# Posts by abdo

Total # Posts: 11

**physics**

a car is traveling with a speed of 15 m/s on a stratight horzontal highway. the wheels of the car have a radius of 50cm.if the car then speeds up with an acceleration of 2 m/s for 5s, find the number of revolution of the wheels during this period.

**math**

please what is the answer

**Algebra**

what is the value of (n) ? (n+3)! = 5040 the prime factorization of 5040 = 2x2x2x2x3x3x5x7 since the ! function involves the multiplication of consecutive integers, it makes sense to arrange these factors so they form consecutive numbers. I got 2,3,4,5,6, and 7 and sure ...

**Trigonometric**

sin3x=(sinx)(3-asin^2x) Wow! is that arcsin^2(x) ??? are we solving for x? or is it proving the identity? proving the identity sin3x=(sinx)(3-sin^2x) Your identity is wrong, it should say: sin3x=(sinx)(3-4sin^2x) try this: sin(3x) = sin(2x + x) = sin2xcosx + cos2xsinx keep ...

**learning**

How is the learning system in British?? http://en.wikipedia.org/wiki/Education_in_the_United_Kingdom =)

**Trigonometic**

Solving Trigonometic Equations solve for x and give the answers as a equations : ( by radian) 1)cos(sinx)=1 <<<and thanks >>> We know sin 2x = 2(sinx)(cosx) so (sinx)(cos)=1/2(sin 2x) So we can change your equation from (sinx)(cosx)=1 to 1/2(sin 2x) = 1 (sin ...

**Trigonometic**

Solving Trigonometic Equations solve for x : ( by radian) 1)cotx= 3 2)secx = 0.5 <<<and thanks >>> 1) Same as tan x = 1/3. Use a calculator. I get 0.321 radians 2) sec x = 0.5 is not possible. The absolute value of the secant must be one or more. << ...

**Trigonometic**

Solving Trigonometic Equations solve for x : 1)sinx = (4/5) 2) cosx = (-12/13) I will do the second one. first of all since the cosine is negative the angle must be in either the second or third quadrants. To find the "angle in standard position" take arccos(+12/13) ...

**Trigonometic**

Solving Trigonometic Equations 1)sinx = (4/5) 2) cosx = (-12/13) Solving Trigonometic Equations 1)sinx = (4/5) 2) cosx = (-12/13) What is the question? Solve for x? x= arcsin (4/5) put that in your calculator. Same for the next. For both cases I recognize the sides of well-...

**Trig........**

I need to prove that the following is true. Thanks (cosx / 1-sinx ) = ( 1+sinx / cosx ) I recall this question causing all kinds of problems when I was still teaching. it requires a little "trick" L.S. =cosx/(1-sinx) multiply top and bottom by 1+sinx, (creating the ...

**Trig.......**

I need to prove that the following is true. Thanks (2tanx /1-tan^x)+(1/2cos^2x-1)= (cosx+sinx)/(cosx - sinx) and thanks ........... check your typing. I tried 30º, the two sides are not equal, they differ by 1 oh , thank you Mr Reiny I'll tell my teacher this Question...