The cosecant is the reciprocal of the sine. The cotangent is the reciprocal of the tangent. The secant is the reciprocal of the cosine. If you have sin x = 3/5, then csc x = 5/3.
The actual fuel used by the IRL is a blend of about 98 percent ethanol and 2 percent denaturant. The exact composition includes a small amount of high-octane racing fuel. The fuel for today's Indy cars has an octane rating of 113, compared with methanol's 107. This means a significant reduction in pre-ignition, or knocking and pinging. In addition, many of the people who handle the fuel, say it smells like tequila.
Answer: A gas RC may use gasoline or it might use nitro fuel. You need to know what kind of engine is in the RC vehicle to know what kind of fuel to use. The non-electric RCs sold in hobby shops are usually nitro RCs that use nitro fuel, not gasoline.