Given a right triangle abc, which of the following statements must be true? check all that apply pic in comments

a) sina=cos (90-c)
b)cosa=sinc
c) sina=cos(90-a)
d) angle a and angle c are supplementry

You notice a very one-dimensional-thinking snail crawling along one rail of a railroad track. naturally, you remove it to a safer place. but before you do, you observe it as it moves from position xi = -92.9 cm to position xf = -64.9 cm along the rail, as measured from a point where one rail abuts the next. what is the snail\'s displacement δx in centimeters?

Give your knowledge of these things in your paper, you will compare and contrast analog and digital signals to determine which is more reliable for encoding and transmitting information. you’ll compare these features: signal shape numerical values for signal measurements amount of data that can be transmitted energy requirements privacy and security (ability of the signal to be encoded in a secret code) clarity of signal in the space provided, write down what you already know about any of these features. if you’re not sure, write down questions you might have about the features.

Consider a double atwood machine constructed as follows: a mass 4m is suspended from a string that passes over a massless pulley on frictionless bearings. the other end of this string supports a second similar pulley, over which passes a second string supporting a mass of 3m at one end and m at the other. using two suitable generalized coordinates, set up the lagrangian and use the lagrange equations to find the acceleration of the mass 4m when the system is released. explain why the top pulley rotates even though it carries equal weights on each side.