# Search results

1. ### Convex Function on Many variables on an interval

Homework Statement Show that f(x) = x1x2 is a convex function on [a,ma]T where a \geq 0 and m \geq 1. Homework Equations By definition f is convex iff \forall x,y\in \Re \quad \wedge \quad \forall \lambda :\quad 0\le \lambda \le 1\quad \Rightarrow \quad f\left( \lambda x+(1-\lambda...
2. ### IBM PC XT Ram question

Hi All, i was looking at the IBM PC XT technical reference and it states that the board can take a maximum of 256K of memory. If you look at the schematic you can then see 36 sockets for memory chips and if you see this picture of it...
3. ### Three - phase transformer

Homework Statement A 2,000 kVA three-phase 33000/6600 V 50 Hz delta - star(wye) connected transformer has a primary and secondary winding resistances of 8 ohms and 0.08 ohms per phase respectively. The leakage reactance referred to the secondary is 1.5 ohms per phase. Calculate the sec...
4. ### Common collector and common emitter

Hi, im trying to build an amplifier with 2 stages, common collector and common emitter. I biased for midpoint operation in them but i have a gain of only 1, dont know where im going wrong. http://yfrog.com/14amplifierunij Thats the circuit, any help is greatly appreciated
5. ### Engineering Collector Current through BJT Circuit

Homework Statement Consider the following circuit http://img109.imageshack.us/img109/80/circuit1.jpg [Broken] IL, current through R3 (unknown resistance must be found) Homework Equations Vth=(Vcc/Rtotal)*R1 (V tThevenin) Rth=R1//R2 (R Thevenin) Vbe= 0.7 volts (silicon...