I have a function which perform some mathematical operations and need a 16gb GPU system, But this function will not be triggered always and rest of time my system will not be in
Currently lambda doesn't have GPU.
However, if you just need to do inference; the emulation via CPU works fine on AWS lambda; here is an article that goes into more details:
https://aws.amazon.com/blogs/machine-learning/how-to-deploy-deep-learning-models-with-aws-lambda-and-tensorflow/