if a+b+c=0 then a³+b³+c³ = ............

-

 As we know that

 a³+b³+c³-3abc = (a+b+c) (a²+b²+c²-ab-bc-ac) 

put value of a+b+c=0 

therefore , 

a³+b³+c³-3abc=0

a³+b³+c³=3abc

correct answer is 3abc

Comments

Post a Comment

Popular posts from this blog

Explain superposition theorem and use the principle of superposition to find the voltage Vo in the circuit

-
Image
Superposition Theorem Requirement: Power System is a complex network having number of voltage and current sources and number of loads. Now to analyze the network we need to find voltage/current at particular branch or load.  In such cases calculations for thevenin's and norton's theorem becomes difficult. We can use superposition theorem to find voltage/current at any branch or load in complex network. In this theorem only one source considered at a time and total voltage/current is sum of voltage/current obtained by considering individual source.   Statement of Superposition Theorem:
Read more

(Solved) An LVDT is connected to an amplifier of gain 250 the output terminals of which are connected to a 5 V voltmeter. The meter's scale can be read to 1/5th of a division and has 100 divisions in all. Given that a core displacement of 0.5 mm provides an output of 2 mV from the LVDT, find, 1. The sensitivity of the LVDT 2. The sensitivity of the whole system 3. The resolution of the instrument in centimeters

-
Image
 Question : An LVDT is connected to an amplifier of gain 250 the output terminals of which are connected to a 5 V voltmeter. The meter's scale can be read to 1/5th of a division and has 100 divisions in all. Given that a core displacement of 0.5 mm provides an output of 2 mV from the LVDT, find,  1. The sensitivity of the LVDT  2. The sensitivity of the whole system  3. The resolution of the instrument in centimeters Explanation : (a) Sensitivity of LVDT = Output voltage /displacement  Sensitivity of LVDT = 2mV/0.5 mm = 4 mV/mm (b)Sensitivity of whole setup = amplification factor*sensitivity of LVDT  Sensitivity of whole setup = 250*(4 mV/mm) = 1000 mV/mm (c) The resolution of the instrument in centimeters = minimum voltage that can be read by instrument /sensitivity of whole setup  There are 100 divisions to measure upto 5V.  So 1 division can read 5/100 = 0.05V Scale can read 1/5 of a division.  So minimum voltage that can be read = 0.05/5 ...
Read more

324 identical galvanic cells, each of internal resistance 9 ohm are arranged as several in series, groups of cell connected in parallel The arrangement has been laid out so that power output in an externally connected resistance of value 4 ohm is maximum. If n cells are connected in every series group that form parallel combination, then find value of n.

-
Image
Question : 324 identical galvanic cells, each of internal resistance 9 ohm are arranged as several in series, groups of cell connected in parallel The arrangement has been laid out so that power output in an externally connected resistance of value 4 ohm is maximum. If n cells are connected in every series group that form parallel combination, then find value of n. Answer : It is asked in question to find value of n such that power transfer to externally connected resistance of value 4 ohm is maximum. 
Read more